Reasons for wanting higher mega pixel count

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Scottelly
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Re: Reasons for wanting higher mega pixel count
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canonpfs wrote:

Much is said about the Sony A7R IV's "too high" mega pixel count. It seems the only reason that people can think of for needing a high mega pixel count is cropping. Besides cropping, here are two additional reasons for wanting more mega pixels:

1. Sharper images. Have you ever looked at an image on your rear LCD and thought that they were sharp only to find them blurry on your home monitor? Yes, I know we should look at our images on the LCD at higher magnifications but please bear with me for a moment. The reason why the blurry images looked sharp on the LCD is because a large image is displayed very small. So you shoot in low light and there is a breeze. You are already at a high ISO to get a higher shutter speed but the flowers in the foreground are still slightly out of focus. With lots of mega pixels available this image can be down sampled. At a smaller size the flowers are now sharp. Taking an image from 61MP down to say 18MP sharpens slightly out of focus areas.

2. Lower noise. Provided the 61MP sensor provides the same high ISO performance as the 42MP sensor the larger sensor will result in lower noise when down sampled. Noise just seems to magically disappear with down sampling. So if you have noise in the 61MP image just down sample it and the perceptible noise will be less.

3. Higher usable ISO. For the same reason as mentioned above the higher mega pixel count allows you to use a higher ISO because the additional noise generated by the higher ISO will be cancelled out by down sampling the image (within reason of course).

So call me crazy if you please but I am very pleased with the higher mega pixel count. It has its uses other than just cropping.

I can't imagine having too many pixels in a photo. Sure, it might slow down my computer. It's time for me to get a new computer anyway, so that would give me an excuse to get one that's maybe four times as fast (mine is 8 years old now), with at least twice the RAM and faster ports. (I only have USB 2, and USB 3 would let me do some things ten times as fast.) Still, I've upgraded my cameras quite a lot to higher resolution models during the time I've had my current computer, and frankly that doesn't seem to slow down my computer that much. Today's 6-core computers with 16 GB of RAM must be so fast that even a 100 MP photo wouldn't slow them down at all.

Cropping is nice, but I just like to be able to see details in my photos that I couldn't see when I shot photos with my 10 MP Sony R1 or my 12 MP Canon 5D. Really big prints seem to just need a lot more pixels to look good, and I want to be able to make really big prints from any photo I shoot. That means I need to shoot the best "quality" photos I can, whenever I shoot photos, but that means taking a tripod with me everywhere these days. Sure, I don't always use it, but I know I should. How can you expect to get sharp pictures if you have motion blur?

Ultimately I think the extra pixels of the new Sony A7r IV will make almost no difference for most people most of the time, but for some people, when they use a tripod or a very fast shutter speed and a really good lens at f5.6 or f4, the image quality will be a bit better, and I like that Sony has decided to let people buy a camera that's capable of doing that. After-all, why limit people who want to shoot really high-definition photos? It seems pretty obvious to me that a lot of people want the extra pixels. Sure, there are those people who are happy with a 20 MP camera, but there are people who are happy with their cell phone photos too. This is real photography (with interchangeable lenses, which is all about more quality really), so why limit people, when the technology is readily available to make sensors that capture more data?

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Scottelly
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Re: Not my experience.
2

Jacques Cornell wrote:

canonpfs wrote:

Much is said about the Sony A7R IV's "too high" mega pixel count. It seems the only reason that people can think of for needing a high mega pixel count is cropping. Besides cropping, here are two additional reasons for wanting more mega pixels:

1. Sharper images. Have you ever looked at an image on your rear LCD and thought that they were sharp only to find them blurry on your home monitor? Yes, I know we should look at our images on the LCD at higher magnifications but please bear with me for a moment. The reason why the blurry images looked sharp on the LCD is because a large image is displayed very small. So you shoot in low light and there is a breeze. You are already at a high ISO to get a higher shutter speed but the flowers in the foreground are still slightly out of focus. With lots of mega pixels available this image can be down sampled. At a smaller size the flowers are now sharp. Taking an image from 61MP down to say 18MP sharpens slightly out of focus areas.

Once you get beyond the minimum ppi (about 200-300) required for output at a certain size, additional pixels are wasted. A postcard printed from a 6MP file looks no less sharp than one from a 42MP file.

That's true, but to get the same quality print at twice the height and width, you can't use that 6 MP file. Instead you have to use a 24 MP file, and that's just for an 8x10. What if you want to print at 16x20? You guessed it, you need four times as many pixels as the 24 MP camera captures, so the 42 MP file just won't do the job. 16x20 is not really common, but there are plenty of people who have a portrait that size. My mom got a portrait of her kids made on medium format film when I was a kid. She got it printed at 40" x 60" (yeah, that's 5 feet across). Luckily there's a couch in the way, so people don't step right up to it, because the image quality just isn't that good. It looks grainy and a bit blurry. Maybe it just wasn't scanned at a high enough resolution. It's getting pretty old now though, so who knows the reason it doesn't look better?

I'm happy Sony decided to unfetter people who want to make big prints or crop a lot. Sure, there are plenty of people who are happy with their 12 MP or 24 MP camera, and they can keep buying those, but for people like me, who dream of a future with ten foot wide 8K screens everywhere, who want the highest resolution possible, Sony has done the right thing. I congratulate them and all the people who will buy the Sony A7r IV.

2. Lower noise. Provided the 61MP sensor provides the same high ISO performance as the 42MP sensor the larger sensor will result in lower noise when down sampled. Noise just seems to magically disappear with down sampling. So if you have noise in the 61MP image just down sample it and the perceptible noise will be less.

Downsample a 42MP a7RII image to 12MP and compare the result to a 12MP a7SII image at the same output size and you will see almost identical noise. More pixels do not reduce noise. Likewise, reducing the number of pixels does not reduce noise. This is because with modern sensor designs, noise is a function of the physical size of the lens aperture (and thus total light collected) regardless of pixel count or sensor size.

3. Higher usable ISO. For the same reason as mentioned above the higher mega pixel count allows you to use a higher ISO because the additional noise generated by the higher ISO will be cancelled out by down sampling the image (within reason of course).

See my response to number 2 above. I get the same usable max ISO from my 24MP a7III and my 42MP a7RIII.

So call me crazy if you please but I am very pleased with the higher mega pixel count. It has its uses other than just cropping.

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Scottelly
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Re: Reasons for wanting higher mega pixel count

Horshack wrote:

canonpfs wrote:

2. Lower noise. Provided the 61MP sensor provides the same high ISO performance as the 42MP sensor the larger sensor will result in lower noise when down sampled. Noise just seems to magically disappear with down sampling. So if you have noise in the 61MP image just down sample it and the perceptible noise will be less.

3. Higher usable ISO. For the same reason as mentioned above the higher mega pixel count allows you to use a higher ISO because the additional noise generated by the higher ISO will be cancelled out by down sampling the image (within reason of course).

This is a oft-quoted theory but is incorrect when you think through it more deeply. The only situation where extra pixels yields can yield better High ISO results in terms of noise and detail (ie, the ability to apply more NR to the higher-resolution image to yield better downsampled results vs an image from a lower-resolution sensor) is when you compare the two using locked-down tripod shots, at identical shutter speeds. In other words, only in an artificial comparison that never can happen in the real world.

The reason it can't happen in the real world is because High ISO is used when you're either shutter speed or DOF/aperture limited. For example, to get a fast enough shutter speed to avoid motion blur from a moving subject or shake blur from hand-holding a camera , or when you need to step down the aperture to get sufficient DOF. In both scenarios if there isn't enough available light to accommodate that faster shutter speed and/or smaller aperture then one must increase ISO in order to maintain the same pixel-level sharpness desired (ie, absence of undesirable blur).

As the pixel density increases one must increase the shutter speed a commensurate amount in order to maintain the same pixel-level sharpness. Pixel-level sharpness is necessary in order to take advantage of the detail advantage from downsampling a higher MP image to achieve better post-NR detail results vs a lower-resolution sensor. Otherwise the higher MP image will just be oversampling motion blur, yielding no detail benefit when downsampled.

Since a higher shutter speed is necessary for a higher MP sensor to achieve the same amount of pixel-level sharpness, the ISO must be increased on the higher MP sensor vs a lower MP sensor. And with that the presumed detail+noise advantage from a higher MP sensor suddenly disappears...because the amount of ISO increase necessary to keep per-pixel sharpness scales directly with pixel density.

As indicated, the only situation where you don't lose the presumed Higher MP advantage is in artificial test scenarios, where you lock both the higher MP and lower MP cameras on a tripod shooting a static, non-moving subject and with both cameras set to identical shutter speeds. In the real world you can't do this because, again, the only reason to use Higher ISO is to avoid blur, so if you have the ability to avoid blur at any shutter speed on a tripod then you would necessarily be using a lower ISO to begin with.

Wrong. I can think of a siuation off the top of my head in less than ten seconds, where what you're saying is incorrect. Take a shot of a night scene, for example. You might want to reduce the motion blur of people walking along a street, so you step up the ISO from 800 to 3200. The rest of the scene is perfectly still, and the camera, which is mounted on a tripod, might still be set up exactly the same as it might othewise be set up at ISO 800 or when using a lower resolution camera, at f5.6 to get the best detail possible, with a reasonable depth of field, rather than opening up the aperture to let in more light and reducing the depth of field. If you're using a normal lens, your depth of field when shooting a subject focused at 50 feet away will be reasonably deep at f5.6, but at f2.8 it's not going to be very deep (mabe 10 feet will be truly sharp). If you want to get detail in distant street light posts and signs in windows, while also getting detail in the person on the bench and cars in the foreground, you can't just open up your aperture to f2.8 (which might be the maxmum aperture of your compact lens, and therefore not an aperture you want to use anyway).

No doubt there are plenty of other situations where more pixels will help to reduce noise, while maintaining or improving the level of detail captured in images. Obviousy a 24 MP camera captures better image quality than an old 6 MP camera can, and the same goes for a 60 MP camera vs a 15 MP camera today. Making up interesting arguments won't stop progress. Just accept that 60 MP is the new 24 MP, and move on.

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Scottelly
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Re: Reasons for wanting higher mega pixel count

pollup wrote:

To me, 24mp is enough in my images and my computer is too slow to handle 61mp. However I'd like to have a 80+mp camera, why? Because this system will save me size, weight and money, as I'll be able to turn that high res camera with a prime lens into a 24mp camera multi prime system. So instead of carrying 3 primes, I carry only one, that's more convenient and cheaper. All we need is the ability for the camera to save small/medium raws, and not only full res raw. Ideally we should be able to specify a resolution, like 24mp, and then the camera will automatically select small/medium/full depending on the crop factor. (I mean, if I'm in crop mode, then maybe I don't want to make the raw even smaller).

Interesting point. Maybe this is why Sony mentioned the 26 MP crop mode. They may be expecting people to carry the 60 MP camera with a 24mm or 35mm lens, and use the crop mode to shoot "normal" focal length photos, so they don't have to use a heavy zoom and can still just carry the camera with one lens most of the time, when they're not doing long telephoto stuff, shooting high-def portraits, or shooting macro stuff. The high resolution sensor does indeed make it a bit more practical to carry a prime as an all-around lens.

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Scottelly
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Re: Is it OK to simply like high resolution?
1

Jonas Palm wrote:

As in, not trying to justify it through some need, but simply enjoying what it provides in an image?

NO! That's not allowed.

The overwhelming majority of my images these days lead a completely digital life. I can wiew them as I like, zoom in on that travelling city scape, check out the fabrics of that traditional japanese wedding dress, the adornements of the notre dame, the insane load of stuff on la sagrada familia, the broche of my elderly mother, and the peculiar colour of her eyes inherited by myself and my daughters.

There is just so much information, so much to see and find.

And I like the pictorial effect when you look at an image and there is more, there is no perceptible limit, the image invites you in, to get closer, and when you do, you get rewarded by even more, pulling you in.

The feeling that you are looking through a clear window into another place and time, rather than a painting of it.

I don’t need it. But I enjoy it.

I'm with you. I like being able to zoom in on parts of a photo to "check it out"  . . . just as I like to travel around in the real world, just to see the various stuff. Why be stuck in the sky, viewing from above? Why be stuck on the highway, only being able to see what you can see through the window of the car as you drive by? Stop, get out of the car, and take a closer look. Having more megapixels in my photos lets me do just that with my photos. Last year I shot a photo of the oldest floating wooden ship. It's in Boston. Today I can look at that photo, and I can zoom in to see the details of the rigging and stuff like that. With a 4 MP camera (my Canon G3), I couldn't capture such great detail. If I had just stuck with that camera for all these years, I don't think I'd be as happy with my photos. I'm seriously thinking of replacing my 36 MP Nikon with the new 60 MP Sony. Sure, it's a lot of money to spend, but one day I just might be glad I spent that money. I'm glad I spend the money on the cameras I have now, so it's a pretty good bet I will appreciate the investment some day in the future. It gives me a sense of satisfaction. Do I need it? Did I need to step up from 4 MP? Really? Probably not, but I did, and I'm glad I did. I'll probably be glad I stepped up to 60 MP too.

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Scottelly
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Re: Aesthetic reasons

hjs_koeln wrote:

Not sure how others feel about it, but to me it´s not only more resolution, from a certain increase on it´s "more resolution plus X". Going from full HD in video to 4k introduces another quality alltogether, and in still photography it is similar.

There´s something fascinating about a tool which allows to exceed the capabilities of the human eye, and resolution is an area where this has become possible (bearing in mind of course that visual physiology is a totally different process than photography).

Digital imagery is immaterial, intangible and therefore elusive, which is kind of a mental stumbling block. There is no original, no ultimate source, b/c copy = original. This sense of digital images being unreal can be compensated by introducing qualities into the digital medium which would not be available otherwise. Again, resolution is one such way, and through it digital photography becomes a tool to reach or create this quality of reality, unobtainable otherwise.

If the immateriality of an image is the price I have to pay to reach this "other" dimension of reality, and if a particular camera is the suitable tool to take me there, I´m willing to go that way.

In this sense, for my taste anyways it can never be enough. A 100mp A7r V, and a 150mp A7r VI? Yes, please!

150 MP files would only be a bit more than twice the size of the monster files from the 60 MP camera, and they would still be far less than 1 GB in size. We can buy 512 GB SD cards today, which means we could shoot more than 500 photos on a single card. The computers today come with 16 GB of RAM, which is more than 16 times as much as a single image from a 150 MP camera. For people to think 60 MP is an unreasonabe size is silly, and in the near future I think even a 150 MP photo will not be unreasonable. We'll soon be at the point where computers come with 32 GB of RAM. In fact, I think the MacBook Pro already comes with that much. Add to that the fact that a 4 TB hard drive, which can hold many thousands of huge raw image files is available for just $100 today, and I don't think even the largest photo files today are too big or "unreasonable" in size. The future is today, and camera companies should offer more high resolution sensors, like Sony is now about to start doing. Computer processing has progressed pretty dramatically in recent years, with notebook computer processors stepping up from dual-core to six cores. Before long we might see processors in notebook computers and even tablets that have 12 cores. I think it's time we see some 100 MP sensors.

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Re: Then 12MP is enough?

Steven Rodgers wrote:

I have a high end 4k monitor.

IIRC sony uses 6K and downsized to get the sharpest 4K video.

Take into account some aggressive cropping and 12MP or 16MP would be enough for your two points. A 12 MP sensor may have less noise due to the larger pixel size, and 6MP is enough for sharp 4K images. And I've seen highly detailed 30 inch prints from 8MP images, so that is covered too.

I think the real reason for more MP is the same reason we buy Dodge Demons. No one here will admit this I bet. I just bought an A7RIII and I drive a car with a large v8 so I am in that group.

Is there really any good reason to get a camera with more than 4 MP? Probably not, becaus if you're using a 4K screen, it's probably a really big screen, and you don't "need" to look at a 30" screen from 8" away. I actually look closely at a 50" screen myself though, so I want more pixels. 4 MP just isn't enough for me. Even 12 MP is disappointing to me these days. I plan to get this 60 MP Sony camera, though I'm not sure when (maybe for my birthday in October, but maybe not until next year, or maybe something else will come out from Nikon or Panasonic, and I won't get it at all).

12 MP is not enough. Even 24 MP is not enough. I'm not even sure if 60 MP will be enough.

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Scottelly
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Re: My only reason. Not a very good reason IMO

nebulla wrote:

dv312 wrote:

Cropping, cropping, and more cropping

Ultra necessary for birding

Everything else is just icing on the cake

I shoot birds, and the megapixels on my camera has nothing to do with it. If you can't get a sharp picture with a camera that has 12-16 or 24 million pixel, you are not going to do it with 100,000 pixels, no matter how much you crop. I won't go into any detail as to what is needed for shooting birds because this is something you first learn to do. My A7iii is enough camera for any situation quite frankly, and the pixel war is a selling tool rather than a benefit.

I get better photos of wildlife with more pixels. Obviously better technique and better lenses helps, but so does more pixels.

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JimKasson
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Re: Reasons for wanting higher mega pixel count
1

Scottelly wrote:

JimKasson wrote:

canonpfs wrote:

Much is said about the Sony A7R IV's "too high" mega pixel count. It seems the only reason that people can think of for needing a high mega pixel count is cropping. Besides cropping, here are two additional reasons for wanting more mega pixels:

1. Sharper images. Have you ever looked at an image on your rear LCD and thought that they were sharp only to find them blurry on your home monitor? Yes, I know we should look at our images on the LCD at higher magnifications but please bear with me for a moment. The reason why the blurry images looked sharp on the LCD is because a large image is displayed very small. So you shoot in low light and there is a breeze. You are already at a high ISO to get a higher shutter speed but the flowers in the foreground are still slightly out of focus. With lots of mega pixels available this image can be down sampled. At a smaller size the flowers are now sharp. Taking an image from 61MP down to say 18MP sharpens slightly out of focus areas.

That is true, but it's a second order effect if the CoC of the blurry flowers is much bigger than the pixel pitch. It occurs because the sharpening algorithms work better with more samples. By the time the CoC gets to 4 or 5 pixel pitches, the improvement is virtually gone.

2. Lower noise. Provided the 61MP sensor provides the same high ISO performance as the 42MP sensor the larger sensor will result in lower noise when down sampled. Noise just seems to magically disappear with down sampling. So if you have noise in the 61MP image just down sample it and the perceptible noise will be less.

This is true if you use nonlinear noise reduction. If you use linear noise reduction, it's pretty close to a wash, since the full well capacity for a given sensor technology is mainly proportional to the area of the pixel.

This is something I've been reading for years and years, yet the new 61 MP Sony sensor offers more dynamic range than a similar sized (full-frame) 42 MP Sony sensor. Since the technology is mature, and since both are back-lit sensors that have basically maxed out their possible fill-factor, shouldn't the 42 MP sensor offer more dynamic range, rather than less, if what you're saying is really true?

You are ignoring the words "for a given sensor technology" in the above. That is meant only to apply within a sensor generation, not across generations.

This concept of photo-sites with larger area being better for dynamic range bothered me when the Nikon D7100 came out, offering more dynamic range than any previous full-frame camera from Nikon or Canon, despite the photo-sites having a much smaller surface area. Nobody was ever able to explain to me why the little, APS-C sensor could capture so much more dynamic range than the older full-frame sensors. Sure, they said there was newer technology in the Nikon D7100 sensor, but that only goes so far, when people continue to make claims like this one you've just made. Given the fact that technology continues to improve, I don't see how what you're saying can be applicable, yet people keep saying stuff like, "They can't get much more out of a sensor, because the limits of the laws of physics have nearly been reached."

Have you ever seen me make that claim, except in the case of QE?

I've read comments like that for more than ten years, yet camera/sensor companies keep on making sensors that have smaller photo-sites, yet can somehow capture more dynamic range.

What are your thoughts on this Jim?

It's unclear to me at this point how much Claff PDR improvement the a7RIV offers over the a7RIII. It is true that full well capacities (FWCs) per square um tend to (fractionally) increase with each generation, and that read noise (RN) tends to decrease, so I would expect some PDR improvement. I would expect EDR -- unnormalized EDR, which is the only form I think makes sense -- to get somewhat better because of RN decreases, but again, at this point the is unknown, as Sony has not provided the protocol for their EDR claims.

Over time, as the pitches become finer, Claff PDR becomes more a measure of RN and less one of FWC, but we are a long way from the RN being the only important component, so, within a generation of sensor technology, I'd expect PDR to be about the same regardless of pitch.

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Re: Reasons for wanting higher mega pixel count

Scottelly wrote:

Horshack wrote:

canonpfs wrote:

2. Lower noise. Provided the 61MP sensor provides the same high ISO performance as the 42MP sensor the larger sensor will result in lower noise when down sampled. Noise just seems to magically disappear with down sampling. So if you have noise in the 61MP image just down sample it and the perceptible noise will be less.

3. Higher usable ISO. For the same reason as mentioned above the higher mega pixel count allows you to use a higher ISO because the additional noise generated by the higher ISO will be cancelled out by down sampling the image (within reason of course).

This is a oft-quoted theory but is incorrect when you think through it more deeply. The only situation where extra pixels yields can yield better High ISO results in terms of noise and detail (ie, the ability to apply more NR to the higher-resolution image to yield better downsampled results vs an image from a lower-resolution sensor) is when you compare the two using locked-down tripod shots, at identical shutter speeds. In other words, only in an artificial comparison that never can happen in the real world.

The reason it can't happen in the real world is because High ISO is used when you're either shutter speed or DOF/aperture limited. For example, to get a fast enough shutter speed to avoid motion blur from a moving subject or shake blur from hand-holding a camera , or when you need to step down the aperture to get sufficient DOF. In both scenarios if there isn't enough available light to accommodate that faster shutter speed and/or smaller aperture then one must increase ISO in order to maintain the same pixel-level sharpness desired (ie, absence of undesirable blur).

As the pixel density increases one must increase the shutter speed a commensurate amount in order to maintain the same pixel-level sharpness. Pixel-level sharpness is necessary in order to take advantage of the detail advantage from downsampling a higher MP image to achieve better post-NR detail results vs a lower-resolution sensor. Otherwise the higher MP image will just be oversampling motion blur, yielding no detail benefit when downsampled.

Since a higher shutter speed is necessary for a higher MP sensor to achieve the same amount of pixel-level sharpness, the ISO must be increased on the higher MP sensor vs a lower MP sensor. And with that the presumed detail+noise advantage from a higher MP sensor suddenly disappears...because the amount of ISO increase necessary to keep per-pixel sharpness scales directly with pixel density.

As indicated, the only situation where you don't lose the presumed Higher MP advantage is in artificial test scenarios, where you lock both the higher MP and lower MP cameras on a tripod shooting a static, non-moving subject and with both cameras set to identical shutter speeds. In the real world you can't do this because, again, the only reason to use Higher ISO is to avoid blur, so if you have the ability to avoid blur at any shutter speed on a tripod then you would necessarily be using a lower ISO to begin with.

Wrong. I can think of a siuation off the top of my head in less than ten seconds, where what you're saying is incorrect. Take a shot of a night scene, for example. You might want to reduce the motion blur of people walking along a street, so you step up the ISO from 800 to 3200.

To reduce the motion blur, you'd increase the shutter speed. Whether or not you increase the ISO is a separate decision. At a base ISO of 800 with an a7RIII, I probably wouldn't increase ISO at all.

https://blog.kasson.com/?s=a7riii+shadow+noise

Jim

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Scottelly
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Re: Reasons for wanting higher mega pixel count
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joger wrote:

unfortunately these discussions are utterly useless.

You'll find two types of people participating:

One group will tell you that its stupid to "waste" pixel you'll never going to see - I have a problem with the framing "wasting" to begin with.

You're oversampling not throwing away pixels - they get used not wasted.

Another group is telling that more is always better without thinking twice what those pixels could do for us.

Truth is that too small pixels might have effects from shrinking the individual pixel and thus can be lower in image quality. There was some years ago a Nokia image sensor with 40 Megapixel in a smartphone camera - this camera only worked acceptable in super bright sunlight since the pixels were too small for the slightest raise in ISO.

With the new A7R IV Sony states that the pixel efficiency was upped to the same level or even above the pixel level of the A7R III due to the better BSI signal conversion plus the new AD conversion. Let's cross fingers this is true.

Noise from sensors with the same generation of signal processing will be similarly noisy in the output result as long as the enlargement doesn't exceed your resolution of your eye.

So yes - an A6 sized print will always look fine - you need maximum 4 MP to exceed the resolution of the human eye with your nose sticking to the postcard.

( Fortunately most of us don't have to earn their money with post card photography )

The two groups argue with good arguments until none of the two is happy at the end.

Truth is that there are many reasons for more 'good' pixels.

  • cropping
  • oversampling
  • image corrections on pixel level
  • pixel level editing

It looks like Sony has upped the pixel level signal : noise ratio quite a bit and thus we should see at the same output size a better image quality compare to the A7R III. The A7R III was already better than the A7R II and better than the A7R.

This will not continue forever. There will be limits in efficiency and to my best knowledge we are in some areas reaching that. Jim has sure some measures for that.

I'd not expect that Sony will bring ongoing more pixels for the "R" models. At some point this will end. My guessing is 70..80 MP for FF might be a natural end and trade off between pixel size and possible efficiency. Maybe the sensor makers have some tricks here and there.

But there will be an end.

Some day there may be an end. I thought it was already here. It seemed like there was a 50 MP barrier. I didn't get it, becaus Sony makes a very capable 1" sensor that captures 20 MP, which is much smaller than 1/4 the size of a full-frame sensor, so even an 80 MP sensor would perform better at a per-pixel level than the current 1" sensor, and that assumes no improvements in technology over time. In a few years we might finally see an 80 MP full-frame senosor. I hope so. I'm wanting a 100 MP sensor. As far as ultimate sensor resolution though, there are 20 MP sensors that are 1/2.3" in size. That's literally a tiny sensor, and many of them would fit on a 1" sensor, so if Sony were to make a full-frame sensor with the same pixel pitch, it would be hundreds of megapixels. How good would the image quality be? I don't know. If sensor fill factors, efficiency, and noise reduction continue to improve, the quality might be fantastic. I don't expect a 200 MP full-frame sensor any time soon though. Look how long it's taken to break the 50 MP barrier. We might not even see a 100 MP sensor for years to come. This new Sony sensor might remain king of high-resolution, full-frame sensors, for years to come.

The current almost 61 MP pixel count seems to work great for Sony and the initial images published look stunning to say the least.

I agree, so they've proven the concept of higher megapixels. I'm hoping Nikon and Canon and even Panasonic will take this to heart and develop their own high-res sensors.

The 'meh' and 'no' sayers forget that we see advantages - the proof is in the pudding.

Agreed, and those same people had the same reaction when sensors started to creep up over 10 MP.

The discussion will have - unfortunately - never an effect since both phenotype groups will never admit that the other one is right ignoring the grey area between them.

This is a social behavior we see in the western world in many formerly civilized and grown up perceived countries.

I am very sad about that.

I don't understand why you think the group of nay-sayers is correct. They're just Luddites, who can't see the future coming. They couldn't see it coming back in 2005, and they won't see it coming in 2020. The future still comes though, and megapixels are greater and greater through the years. One day all digital cameras will capture the equivalent of 200 MP or more. That future is coming, but when it will be here I do not know. It might be in 2030 or it might not happen until 2050, but it's coming.

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JimKasson
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Re: Reasons for wanting higher mega pixel count

ActionPhotoPassion wrote:

CE3 wrote:

The main reason I like the higher mega pixels is for increased sharpness

Well a micro shake on the 42Mpx sensor is unforgiving for the result of an image where on the 24Mpx sensor you can still use the image.

For the same print size, the blurring effect of camera motion is unrelated to pixel pitch.

So saying that sharpness increases with the Mpx is only dependant of the operator.

That is certainly true.

Now if like md you're more often on a tripod than handheld of course you won't have any problem

Well, there is also defocus blur...

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Scottelly
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Re: Reasons for wanting higher mega pixel count

JimKasson wrote:

Scottelly wrote:

JimKasson wrote:

canonpfs wrote:

Much is said about the Sony A7R IV's "too high" mega pixel count. It seems the only reason that people can think of for needing a high mega pixel count is cropping. Besides cropping, here are two additional reasons for wanting more mega pixels:

1. Sharper images. Have you ever looked at an image on your rear LCD and thought that they were sharp only to find them blurry on your home monitor? Yes, I know we should look at our images on the LCD at higher magnifications but please bear with me for a moment. The reason why the blurry images looked sharp on the LCD is because a large image is displayed very small. So you shoot in low light and there is a breeze. You are already at a high ISO to get a higher shutter speed but the flowers in the foreground are still slightly out of focus. With lots of mega pixels available this image can be down sampled. At a smaller size the flowers are now sharp. Taking an image from 61MP down to say 18MP sharpens slightly out of focus areas.

That is true, but it's a second order effect if the CoC of the blurry flowers is much bigger than the pixel pitch. It occurs because the sharpening algorithms work better with more samples. By the time the CoC gets to 4 or 5 pixel pitches, the improvement is virtually gone.

2. Lower noise. Provided the 61MP sensor provides the same high ISO performance as the 42MP sensor the larger sensor will result in lower noise when down sampled. Noise just seems to magically disappear with down sampling. So if you have noise in the 61MP image just down sample it and the perceptible noise will be less.

This is true if you use nonlinear noise reduction. If you use linear noise reduction, it's pretty close to a wash, since the full well capacity for a given sensor technology is mainly proportional to the area of the pixel.

This is something I've been reading for years and years, yet the new 61 MP Sony sensor offers more dynamic range than a similar sized (full-frame) 42 MP Sony sensor. Since the technology is mature, and since both are back-lit sensors that have basically maxed out their possible fill-factor, shouldn't the 42 MP sensor offer more dynamic range, rather than less, if what you're saying is really true?

You are ignoring the words "for a given sensor technology" in the above.

I see, but what's the point in talking about full-well capacity limits, as they relate to are of the sensor and density, if the technology is constantly changing, and the ratio doesn't apply, since the sensor is new vs the old one you're comparing it to? This bothers me, because if things are not limited by physics, but only by the technology used, and the technology is not static, there seems to be no point in mentioning the full-well capacity and the number of pixels vs sensor area.

That is meant only to apply within a sensor generation, not across generations.

Then there's no point in mentioning this stuff, because the new sensor is not from the same generation, right?

This concept of photo-sites with larger area being better for dynamic range bothered me when the Nikon D7100 came out, offering more dynamic range than any previous full-frame camera from Nikon or Canon, despite the photo-sites having a much smaller surface area. Nobody was ever able to explain to me why the little, APS-C sensor could capture so much more dynamic range than the older full-frame sensors. Sure, they said there was newer technology in the Nikon D7100 sensor, but that only goes so far, when people continue to make claims like this one you've just made. Given the fact that technology continues to improve, I don't see how what you're saying can be applicable, yet people keep saying stuff like, "They can't get much more out of a sensor, because the limits of the laws of physics have nearly been reached."

Have you ever seen me make that claim, except in the case of QE?

Well, you seem to be alluding to the same old claims that it's physics, but it's not, because it's technology, and that's constantly changing, isn't it? You qualify your statement above by mentioning the "given sensor technology" right? What's the point in mentioning all the other stuff, if you're going to basically negate what you said by "qualifying" it with an out phrase?

I've read comments like that for more than ten years, yet camera/sensor companies keep on making sensors that have smaller photo-sites, yet can somehow capture more dynamic range.

What are your thoughts on this Jim?

It's unclear to me at this point how much Claff PDR improvement the a7RIV offers over the a7RIII.

Of course. Sony's claiming 15 stops. It will be interesting to see what Bill's calculations show.

It is true that full well capacities (FWCs) per square um tend to (fractionally) increase with each generation, and that read noise (RN) tends to decrease,

And that seems almost impossible, when we read some of the things we read about limits of physics in sensor noise, but improvemets keep on happening. It's amazing.

so I would expect some PDR improvement. I would expect EDR -- unnormalized EDR, which is the only form I think makes sense -- to get somewhat better because of RN decreases, but again, at this point the is unknown, as Sony has not provided the protocol for their EDR claims.

Over time, as the pitches become finer, Claff PDR becomes more a measure of RN and less one of FWC, but we are a long way from the RN being the only important component, so, within a generation of sensor technology, I'd expect PDR to be about the same regardless of pitch.

O.K, but it's almost never within the same generation, right? This new Sony sensor is going to be compared to sensors from older generations, like the Nikon 45 MP sensor and the Sony 42 MP sensor and even the really old Canon 50 MP sensor. It might be compared to the new Fuji sensor too, but then the massive difference in size comes into play, and we'd be comparing apples with oranges.

All I can think is that this sensor is new and in a camera that's in the same price range, so it's probably significantly better. That seems to be the way it goes pretty much every time.

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Scottelly
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Re: Then 12MP is enough?

sportyaccordy wrote:

Steven Rodgers wrote:

I have a high end 4k monitor.

IIRC sony uses 6K and downsized to get the sharpest 4K video.

Take into account some aggressive cropping and 12MP or 16MP would be enough for your two points. A 12 MP sensor may have less noise due to the larger pixel size, and 6MP is enough for sharp 4K images. And I've seen highly detailed 30 inch prints from 8MP images, so that is covered too.

I think the real reason for more MP is the same reason we buy Dodge Demons. No one here will admit this I bet. I just bought an A7RIII and I drive a car with a large v8 so I am in that group.

According to people a lot smarter than me, when you factor in the losses from a Bayer filter the effective color resolution is about 1/2 the native resolution (with a bias towards greens). You also have to factor in aspect ratio. To view a full 3:2 photo you only get about 6 of the 8MP of your 4K monitor. So to that end 12MP is all that's "needed".

That said I have 6MP photos from my D40 that look great on my 4K monitor.

Well I can tell you that the 10 MP photos from my Sony R1 do NOT look great on my 4K screen, but it's a 50" screen, so maybe that's why. That said, the 14.7 MP photos from my Merrill and Quattro cameras really look great on that screen, as do the 36 MP photos from my Nikon D810.

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JimKasson
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Re: Reasons for wanting higher mega pixel count

Scottelly wrote:

JimKasson wrote:

Scottelly wrote:

JimKasson wrote:

canonpfs wrote:

Much is said about the Sony A7R IV's "too high" mega pixel count. It seems the only reason that people can think of for needing a high mega pixel count is cropping. Besides cropping, here are two additional reasons for wanting more mega pixels:

1. Sharper images. Have you ever looked at an image on your rear LCD and thought that they were sharp only to find them blurry on your home monitor? Yes, I know we should look at our images on the LCD at higher magnifications but please bear with me for a moment. The reason why the blurry images looked sharp on the LCD is because a large image is displayed very small. So you shoot in low light and there is a breeze. You are already at a high ISO to get a higher shutter speed but the flowers in the foreground are still slightly out of focus. With lots of mega pixels available this image can be down sampled. At a smaller size the flowers are now sharp. Taking an image from 61MP down to say 18MP sharpens slightly out of focus areas.

That is true, but it's a second order effect if the CoC of the blurry flowers is much bigger than the pixel pitch. It occurs because the sharpening algorithms work better with more samples. By the time the CoC gets to 4 or 5 pixel pitches, the improvement is virtually gone.

2. Lower noise. Provided the 61MP sensor provides the same high ISO performance as the 42MP sensor the larger sensor will result in lower noise when down sampled. Noise just seems to magically disappear with down sampling. So if you have noise in the 61MP image just down sample it and the perceptible noise will be less.

This is true if you use nonlinear noise reduction. If you use linear noise reduction, it's pretty close to a wash, since the full well capacity for a given sensor technology is mainly proportional to the area of the pixel.

This is something I've been reading for years and years, yet the new 61 MP Sony sensor offers more dynamic range than a similar sized (full-frame) 42 MP Sony sensor. Since the technology is mature, and since both are back-lit sensors that have basically maxed out their possible fill-factor, shouldn't the 42 MP sensor offer more dynamic range, rather than less, if what you're saying is really true?

You are ignoring the words "for a given sensor technology" in the above.

I see, but what's the point in talking about full-well capacity limits, as they relate to are of the sensor and density, if the technology is constantly changing, and the ratio doesn't apply, since the sensor is new vs the old one you're comparing it to? This bothers me, because if things are not limited by physics, but only by the technology used, and the technology is not static, there seems to be no point in mentioning the full-well capacity and the number of pixels vs sensor area.

That is meant only to apply within a sensor generation, not across generations.

Then there's no point in mentioning this stuff, because the new sensor is not from the same generation, right?

I was offering general information. The FWC and the RN numbers for the a7RIV are as far as I know unavailable, so it is impossible for me to offer specific information. It appears that I have offended you. If you find the information that I've posted useless, please ignore it.

This concept of photo-sites with larger area being better for dynamic range bothered me when the Nikon D7100 came out, offering more dynamic range than any previous full-frame camera from Nikon or Canon, despite the photo-sites having a much smaller surface area. Nobody was ever able to explain to me why the little, APS-C sensor could capture so much more dynamic range than the older full-frame sensors. Sure, they said there was newer technology in the Nikon D7100 sensor, but that only goes so far, when people continue to make claims like this one you've just made. Given the fact that technology continues to improve, I don't see how what you're saying can be applicable, yet people keep saying stuff like, "They can't get much more out of a sensor, because the limits of the laws of physics have nearly been reached."

Have you ever seen me make that claim, except in the case of QE?

Well, you seem to be alluding to the same old claims that it's physics, but it's not, because it's technology, and that's constantly changing, isn't it?

Are you suggesting that QE's in excess of unity are on the horizon?

You qualify your statement above by mentioning the "given sensor technology" right? What's the point in mentioning all the other stuff, if you're going to basically negate what you said by "qualifying" it with an out phrase?

Again, please ignore what I've said if you find it inappropriate.

I've read comments like that for more than ten years, yet camera/sensor companies keep on making sensors that have smaller photo-sites, yet can somehow capture more dynamic range.

What are your thoughts on this Jim?

It's unclear to me at this point how much Claff PDR improvement the a7RIV offers over the a7RIII.

Of course. Sony's claiming 15 stops. It will be interesting to see what Bill's calculations show.

It is true that full well capacities (FWCs) per square um tend to (fractionally) increase with each generation, and that read noise (RN) tends to decrease,

And that seems almost impossible,

Why do you say that? There is no physical limit to FWC that I know.

when we read some of the things we read about limits of physics in sensor noise,

What things?

but improvemets keep on happening. It's amazing.

Within limits, it's predictable. Look at the curves for disk areal density vs time. Or transistors per unit area. There are gross effects that change those curves over a long enough time, but you can go a long way towards making many prections with a ruler and a piece of log paper.

so I would expect some PDR improvement. I would expect EDR -- unnormalized EDR, which is the only form I think makes sense -- to get somewhat better because of RN decreases, but again, at this point the is unknown, as Sony has not provided the protocol for their EDR claims.

Over time, as the pitches become finer, Claff PDR becomes more a measure of RN and less one of FWC, but we are a long way from the RN being the only important component, so, within a generation of sensor technology, I'd expect PDR to be about the same regardless of pitch.

O.K, but it's almost never within the same generation, right? This new Sony sensor is going to be compared to sensors from older generations, like the Nikon 45 MP sensor and the Sony 42 MP sensor and even the really old Canon 50 MP sensor. It might be compared to the new Fuji sensor too, but then the massive difference in size comes into play, and we'd be comparing apples with oranges.

All I can think is that this sensor is new and in a camera that's in the same price range, so it's probably significantly better. That seems to be the way it goes pretty much every time.

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Jacques Cornell
Jacques Cornell Forum Pro • Posts: 11,758
Re: Reasons for wanting higher mega pixel count

Cudacke Dees wrote:

Jacques Cornell wrote:

Cudacke Dees wrote:

10 years ago people say 12MP is enough.
12MP which is 4272 x 2848 on Sony camera.

It is only slightly larger than my 8MP 4K resolution 15 inch HP spectre x360 laptop screen which I look at every day no farther than 2 foot.
I won't even be able to APS-C crop it and still get a full screen image.

with 24MP a APS-C crop barely larger.

so yea unless you are planning to die in 10 years.....

What's your point? Ten years later, a 12MP file is still sufficient to display full-screen without upscaling on a 4K display of any size or to make a print at least 12"x18". If your laptop 10 years from now has an 8K display, your eyes won't be able to discern the difference.

what do you mean?

I am already seeing the difference on my 15 inch 4K screen every day.

I don't believe you. Or rather, I don't believe that what you're seeing results from increased resolution in the original file. 4K is 8MP. TBH, I have not done a controlled test with my 12MP, 14MP, 16MP, 20MP, 24MP and 42MP cameras, but it is my belief that files from these cameras, downsampled to 8MP, will show identical levels of detail. This conversation has made me curious to see the results of such a test, but it is of little practical value to me - given that my 180ppi large prints look great to me and my customers - and I don't have the time to chase phantoms simply for the sake of educating others.

Do you have an 8K display and 61MP camera to see the difference from 4K can not be seen?

Do you?

that is my point.

That is not a point. It's a question.

so yea unless you are planning to die in 10 years.....

The technology is improving.
What people say enough 10 years ago already reaches it limits.

Everything has limits. But, the limits to what you can do with a 12MP file are no different now than they were 10 years ago.

If you want to print bigger than this or view on a 5K or higher-rez display and view at abnormally close distances, then yes, it helps to have more than 12MP.

12 MP only barely bigger than my 15 inch 4K display with an APS-c crop it is smaller than my screen.

The size of the pixels on a 4K 15" display are well below what the naked human eye can resolve.

I can see the difference every day by just using it normally.

Well, when viewing images full-screen (not 1:1) on my 4K 32" display, I don't notice any difference in detail between files of any resolution greater than the 8MP required to fill the screen. Even images from my 12MP LF1 compact look crisp and detailed. The pixel pitch of this display is about 136ppi, which equates to roughly 180ppi in a 12"x18" print. And, I know from experience that a 12MP file can yield a very crisp and detailed print of this size, and I've seen 8MP prints much larger than this that looked amazing.

you don't need to make big prints... you just need a new computer too see it. or maybe a good eye doctor would help in your case if you really cannot tell.

Now you're just being obnoxious, so you're going on my ignore list. Bye.

But, now we're talking about exceeding 42MP, which is a very much higher threshold and one that 99% of photographers will never surpass.

oh well I am not 99% then (where is this # coming from???)

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Jacques Cornell
Jacques Cornell Forum Pro • Posts: 11,758
Re: Then 12MP is enough?

Scottelly wrote:

sportyaccordy wrote:

Steven Rodgers wrote:

I have a high end 4k monitor.

IIRC sony uses 6K and downsized to get the sharpest 4K video.

Take into account some aggressive cropping and 12MP or 16MP would be enough for your two points. A 12 MP sensor may have less noise due to the larger pixel size, and 6MP is enough for sharp 4K images. And I've seen highly detailed 30 inch prints from 8MP images, so that is covered too.

I think the real reason for more MP is the same reason we buy Dodge Demons. No one here will admit this I bet. I just bought an A7RIII and I drive a car with a large v8 so I am in that group.

According to people a lot smarter than me, when you factor in the losses from a Bayer filter the effective color resolution is about 1/2 the native resolution (with a bias towards greens). You also have to factor in aspect ratio. To view a full 3:2 photo you only get about 6 of the 8MP of your 4K monitor. So to that end 12MP is all that's "needed".

That said I have 6MP photos from my D40 that look great on my 4K monitor.

Well I can tell you that the 10 MP photos from my Sony R1 do NOT look great on my 4K screen, but it's a 50" screen, so maybe that's why.

Viewing up close, you'll be able to make out the individual pixels on that display, so it's not going to look crisp. You'll need to view it from about six feet away for the pixels to appear sufficiently small that you can't make them out. At that distance, a properly sharpened image with at least 8MP of captured detail should look crisp. If the lens on your R1 isn't great, though, you may not be getting a full 10MP or even 8MP of captured detail.

That said, the 14.7 MP photos from my Merrill and Quattro cameras really look great on that screen, as do the 36 MP photos from my Nikon D810.

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Scottelly
Scottelly Forum Pro • Posts: 14,045
Re: Reasons for wanting higher mega pixel count

JimKasson wrote:

Scottelly wrote:

JimKasson wrote:

Scottelly wrote:

JimKasson wrote:

canonpfs wrote:

Much is said about the Sony A7R IV's "too high" mega pixel count. It seems the only reason that people can think of for needing a high mega pixel count is cropping. Besides cropping, here are two additional reasons for wanting more mega pixels:

1. Sharper images. Have you ever looked at an image on your rear LCD and thought that they were sharp only to find them blurry on your home monitor? Yes, I know we should look at our images on the LCD at higher magnifications but please bear with me for a moment. The reason why the blurry images looked sharp on the LCD is because a large image is displayed very small. So you shoot in low light and there is a breeze. You are already at a high ISO to get a higher shutter speed but the flowers in the foreground are still slightly out of focus. With lots of mega pixels available this image can be down sampled. At a smaller size the flowers are now sharp. Taking an image from 61MP down to say 18MP sharpens slightly out of focus areas.

That is true, but it's a second order effect if the CoC of the blurry flowers is much bigger than the pixel pitch. It occurs because the sharpening algorithms work better with more samples. By the time the CoC gets to 4 or 5 pixel pitches, the improvement is virtually gone.

2. Lower noise. Provided the 61MP sensor provides the same high ISO performance as the 42MP sensor the larger sensor will result in lower noise when down sampled. Noise just seems to magically disappear with down sampling. So if you have noise in the 61MP image just down sample it and the perceptible noise will be less.

This is true if you use nonlinear noise reduction. If you use linear noise reduction, it's pretty close to a wash, since the full well capacity for a given sensor technology is mainly proportional to the area of the pixel.

This is something I've been reading for years and years, yet the new 61 MP Sony sensor offers more dynamic range than a similar sized (full-frame) 42 MP Sony sensor. Since the technology is mature, and since both are back-lit sensors that have basically maxed out their possible fill-factor, shouldn't the 42 MP sensor offer more dynamic range, rather than less, if what you're saying is really true?

You are ignoring the words "for a given sensor technology" in the above.

I see, but what's the point in talking about full-well capacity limits, as they relate to are of the sensor and density, if the technology is constantly changing, and the ratio doesn't apply, since the sensor is new vs the old one you're comparing it to? This bothers me, because if things are not limited by physics, but only by the technology used, and the technology is not static, there seems to be no point in mentioning the full-well capacity and the number of pixels vs sensor area.

That is meant only to apply within a sensor generation, not across generations.

Then there's no point in mentioning this stuff, because the new sensor is not from the same generation, right?

I was offering general information. The FWC and the RN numbers for the a7RIV are as far as I know unavailable, so it is impossible for me to offer specific information. It appears that I have offended you. If you find the information that I've posted useless, please ignore it.

Sorry, but it just seems like a form of misinformation to me. I've been mislead in the past to think things that weren't true, and as a result I ended up spending more money than I probably should have at the time. It didn't hurt me per say, but it bothers me when I see things that I think are misleading.

This concept of photo-sites with larger area being better for dynamic range bothered me when the Nikon D7100 came out, offering more dynamic range than any previous full-frame camera from Nikon or Canon, despite the photo-sites having a much smaller surface area. Nobody was ever able to explain to me why the little, APS-C sensor could capture so much more dynamic range than the older full-frame sensors. Sure, they said there was newer technology in the Nikon D7100 sensor, but that only goes so far, when people continue to make claims like this one you've just made. Given the fact that technology continues to improve, I don't see how what you're saying can be applicable, yet people keep saying stuff like, "They can't get much more out of a sensor, because the limits of the laws of physics have nearly been reached."

Have you ever seen me make that claim, except in the case of QE?

Well, you seem to be alluding to the same old claims that it's physics, but it's not, because it's technology, and that's constantly changing, isn't it?

Are you suggesting that QE's in excess of unity are on the horizon?

I'm saying that we are not reaching the limits of physics, but only the limits of today's technology, and that will change tomorrow or next week or next year, and for people to think there is some physical limit, because of the thing people suggest are happening, is a mistake. People should not be mislead by things that people say that seem to be about physical limits, because it's not the physical limits that we are approaching. It's just the limits of today's technology, and next year or the year after there will be a better sensor that lets photographers do things they can't do with today's best sensor.

You qualify your statement above by mentioning the "given sensor technology" right? What's the point in mentioning all the other stuff, if you're going to basically negate what you said by "qualifying" it with an out phrase?

Again, please ignore what I've said if you find it inappropriate.

I'd rather not ignore things that I find inappropriate. "The only thing that evil needs to succeed is for good men to do nothing." Not that I'm saying what you wrote is evil, but if I don't agree with something, I think it's my duty to say so, and either find out why I am wrong, or convince others that what I think is right. There are limits, of course, but as I read through forums here, if I see something that bothers me, and I think I have something helpful or useful to say, then I normally say it, as I'm sure you do too.

I've read comments like that for more than ten years, yet camera/sensor companies keep on making sensors that have smaller photo-sites, yet can somehow capture more dynamic range.

What are your thoughts on this Jim?

It's unclear to me at this point how much Claff PDR improvement the a7RIV offers over the a7RIII.

Of course. Sony's claiming 15 stops. It will be interesting to see what Bill's calculations show.

It is true that full well capacities (FWCs) per square um tend to (fractionally) increase with each generation, and that read noise (RN) tends to decrease,

And that seems almost impossible,

Why do you say that? There is no physical limit to FWC that I know.

I was just commenting about the fact that full well capacities per square um tend to increase with each generation. I'd think at some point they'd reach a maximum, but that just doesn't seem to happen. The sensor manufacturers just keep finding ways to make smaller photo-sites catch more energy. I guess it's like the efficiency of solar panels though. They've got a long way to go, though we were mislead to believe they were about at their maximum possible efficiency years ago.

when we read some of the things we read about limits of physics in sensor noise,

What things?

but improvemets keep on happening. It's amazing.

Within limits, it's predictable. Look at the curves for disk areal density vs time. Or transistors per unit area. There are gross effects that change those curves over a long enough time, but you can go a long way towards making many prections with a ruler and a piece of log paper.

so I would expect some PDR improvement. I would expect EDR -- unnormalized EDR, which is the only form I think makes sense -- to get somewhat better because of RN decreases, but again, at this point the is unknown, as Sony has not provided the protocol for their EDR claims.

Over time, as the pitches become finer, Claff PDR becomes more a measure of RN and less one of FWC, but we are a long way from the RN being the only important component, so, within a generation of sensor technology, I'd expect PDR to be about the same regardless of pitch.

O.K, but it's almost never within the same generation, right? This new Sony sensor is going to be compared to sensors from older generations, like the Nikon 45 MP sensor and the Sony 42 MP sensor and even the really old Canon 50 MP sensor. It might be compared to the new Fuji sensor too, but then the massive difference in size comes into play, and we'd be comparing apples with oranges.

All I can think is that this sensor is new and in a camera that's in the same price range, so it's probably significantly better. That seems to be the way it goes pretty much every time.

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sebbe Contributing Member • Posts: 980
Re: Reasons for wanting higher mega pixel count

1. Cropping

2. Total Scene without the need to shoot additional details for jobs like location scouting.

3. Whole piece of work without the need to shoot additional details for documentation.

4. Bigger DOF in low light situations: A step back+crop instead of higher aperture.

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JimKasson
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Re: Reasons for wanting higher mega pixel count

Scottelly wrote:

JimKasson wrote:

Scottelly wrote:

JimKasson wrote:

Scottelly wrote:

JimKasson wrote:

canonpfs wrote:

Much is said about the Sony A7R IV's "too high" mega pixel count. It seems the only reason that people can think of for needing a high mega pixel count is cropping. Besides cropping, here are two additional reasons for wanting more mega pixels:

1. Sharper images. Have you ever looked at an image on your rear LCD and thought that they were sharp only to find them blurry on your home monitor? Yes, I know we should look at our images on the LCD at higher magnifications but please bear with me for a moment. The reason why the blurry images looked sharp on the LCD is because a large image is displayed very small. So you shoot in low light and there is a breeze. You are already at a high ISO to get a higher shutter speed but the flowers in the foreground are still slightly out of focus. With lots of mega pixels available this image can be down sampled. At a smaller size the flowers are now sharp. Taking an image from 61MP down to say 18MP sharpens slightly out of focus areas.

That is true, but it's a second order effect if the CoC of the blurry flowers is much bigger than the pixel pitch. It occurs because the sharpening algorithms work better with more samples. By the time the CoC gets to 4 or 5 pixel pitches, the improvement is virtually gone.

2. Lower noise. Provided the 61MP sensor provides the same high ISO performance as the 42MP sensor the larger sensor will result in lower noise when down sampled. Noise just seems to magically disappear with down sampling. So if you have noise in the 61MP image just down sample it and the perceptible noise will be less.

This is true if you use nonlinear noise reduction. If you use linear noise reduction, it's pretty close to a wash, since the full well capacity for a given sensor technology is mainly proportional to the area of the pixel.

This is something I've been reading for years and years, yet the new 61 MP Sony sensor offers more dynamic range than a similar sized (full-frame) 42 MP Sony sensor. Since the technology is mature, and since both are back-lit sensors that have basically maxed out their possible fill-factor, shouldn't the 42 MP sensor offer more dynamic range, rather than less, if what you're saying is really true?

You are ignoring the words "for a given sensor technology" in the above.

I see, but what's the point in talking about full-well capacity limits, as they relate to are of the sensor and density, if the technology is constantly changing, and the ratio doesn't apply, since the sensor is new vs the old one you're comparing it to? This bothers me, because if things are not limited by physics, but only by the technology used, and the technology is not static, there seems to be no point in mentioning the full-well capacity and the number of pixels vs sensor area.

That is meant only to apply within a sensor generation, not across generations.

Then there's no point in mentioning this stuff, because the new sensor is not from the same generation, right?

I was offering general information. The FWC and the RN numbers for the a7RIV are as far as I know unavailable, so it is impossible for me to offer specific information. It appears that I have offended you. If you find the information that I've posted useless, please ignore it.

Sorry, but it just seems like a form of misinformation to me.

Misinformation: "false or inaccurate information, especially that which is deliberately intended to deceive"

In what sense is anything that I have written false?

Are you saying that I intend to deceive?

I've been mislead in the past to think things that weren't true, and as a result I ended up spending more money than I probably should have at the time. It didn't hurt me per say, but it bothers me when I see things that I think are misleading.

This concept of photo-sites with larger area being better for dynamic range bothered me when the Nikon D7100 came out, offering more dynamic range than any previous full-frame camera from Nikon or Canon, despite the photo-sites having a much smaller surface area. Nobody was ever able to explain to me why the little, APS-C sensor could capture so much more dynamic range than the older full-frame sensors. Sure, they said there was newer technology in the Nikon D7100 sensor, but that only goes so far, when people continue to make claims like this one you've just made. Given the fact that technology continues to improve, I don't see how what you're saying can be applicable, yet people keep saying stuff like, "They can't get much more out of a sensor, because the limits of the laws of physics have nearly been reached."

Have you ever seen me make that claim, except in the case of QE?

Well, you seem to be alluding to the same old claims that it's physics, but it's not, because it's technology, and that's constantly changing, isn't it?

Are you suggesting that QE's in excess of unity are on the horizon?

I'm saying that we are not reaching the limits of physics, but only the limits of today's technology, and that will change tomorrow or next week or next year, and for people to think there is some physical limit, because of the thing people suggest are happening, is a mistake.

I think a QE of greater than 1 is a limit, unless you have electron cascades, which doesn't really help.

Why is it not a limit?

People should not be mislead by things that people say that seem to be about physical limits, because it's not the physical limits that we are approaching. It's just the limits of today's technology, and next year or the year after there will be a better sensor that lets photographers do things they can't do with today's best sensor.

You qualify your statement above by mentioning the "given sensor technology" right? What's the point in mentioning all the other stuff, if you're going to basically negate what you said by "qualifying" it with an out phrase?

Again, please ignore what I've said if you find it inappropriate.

I'd rather not ignore things that I find inappropriate. "The only thing that evil needs to succeed is for good men to do nothing." Not that I'm saying what you wrote is evil, but if I don't agree with something, I think it's my duty to say so, and either find out why I am wrong, or convince others that what I think is right. There are limits, of course, but as I read through forums here, if I see something that bothers me, and I think I have something helpful or useful to say, then I normally say it, as I'm sure you do too.

I've read comments like that for more than ten years, yet camera/sensor companies keep on making sensors that have smaller photo-sites, yet can somehow capture more dynamic range.

What are your thoughts on this Jim?

It's unclear to me at this point how much Claff PDR improvement the a7RIV offers over the a7RIII.

Of course. Sony's claiming 15 stops. It will be interesting to see what Bill's calculations show.

It is true that full well capacities (FWCs) per square um tend to (fractionally) increase with each generation, and that read noise (RN) tends to decrease,

And that seems almost impossible,

Why do you say that? There is no physical limit to FWC that I know.

I was just commenting about the fact that full well capacities per square um tend to increase with each generation.

You said it was "almost impossible". Why should it be so?  Trees don't grow to the sky, but FWCs aren't like QE, where we're within a binary order of magnitude of theoretical.

I'd think at some point they'd reach a maximum, but that just doesn't seem to happen. The sensor manufacturers just keep finding ways to make smaller photo-sites catch more energy. I guess it's like the efficiency of solar panels though. They've got a long way to go, though we were mislead to believe they were about at their maximum possible efficiency years ago.

I never saw any such claim about solar panels, and I have been reading about them in IEEE publications for years.

when we read some of the things we read about limits of physics in sensor noise,

What things?

but improvemets keep on happening. It's amazing.

Within limits, it's predictable. Look at the curves for disk areal density vs time. Or transistors per unit area. There are gross effects that change those curves over a long enough time, but you can go a long way towards making many prections with a ruler and a piece of log paper.

so I would expect some PDR improvement. I would expect EDR -- unnormalized EDR, which is the only form I think makes sense -- to get somewhat better because of RN decreases, but again, at this point the is unknown, as Sony has not provided the protocol for their EDR claims.

Over time, as the pitches become finer, Claff PDR becomes more a measure of RN and less one of FWC, but we are a long way from the RN being the only important component, so, within a generation of sensor technology, I'd expect PDR to be about the same regardless of pitch.

O.K, but it's almost never within the same generation, right? This new Sony sensor is going to be compared to sensors from older generations, like the Nikon 45 MP sensor and the Sony 42 MP sensor and even the really old Canon 50 MP sensor. It might be compared to the new Fuji sensor too, but then the massive difference in size comes into play, and we'd be comparing apples with oranges.

All I can think is that this sensor is new and in a camera that's in the same price range, so it's probably significantly better. That seems to be the way it goes pretty much every time.

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