nigelht

Joined on Sep 2, 2012

Comments

Total: 66, showing: 1 – 20
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On article What is equivalence and why should I care? (2451 comments in total)
In reply to:

Ruekon: Thank you for this article and the effort spent to make the comparisons and answer lots of comments!

Take Nikon 1 for example: it ships with a 10-30mm f/3.5-5.6 kit lens. People come to the conclusion that picture quality doesn't catch up with larger sensor cameras. Which surprise when considering that the lens is equivalent to 27-81 f/9.5-15. Don't even people at Nikon know about this and rather tend to stop the Nikon 1 instead?

https://fstoppers.com/sports/pro-photographer-using-his-iphone-photograph-olympics-5568

Link | Posted on May 24, 2017 at 13:56 UTC
On article What is equivalence and why should I care? (2451 comments in total)
In reply to:

Ruekon: Thank you for this article and the effort spent to make the comparisons and answer lots of comments!

Take Nikon 1 for example: it ships with a 10-30mm f/3.5-5.6 kit lens. People come to the conclusion that picture quality doesn't catch up with larger sensor cameras. Which surprise when considering that the lens is equivalent to 27-81 f/9.5-15. Don't even people at Nikon know about this and rather tend to stop the Nikon 1 instead?

@Richard Butler

No confusion?

Then pray tell what is the "conventional exposure model"? You know, the one that tells you the relationship between ISO, aperture and shutter speed for exposure, AKA the exposure triangle...

How is a 50mm f2 equivalent aperture to 135mm f5.4 in the "conventional exposure model"? It's not because you have to increase ISO. Which is fine unless you are already at the limit of ISO.

When does it matter? When you are already at the end of your native ISO trying to shoot a high school football game at 30-50 foot candles illumination at 1/1000.

As far as how CX is shot, folks who use it for birding really are only using the central 14% of a FX image and then cropping more.

Calling the 70-300CX the equivalent of an 810mm f15 lens leads to the confusion of thinking it won't be good for birding because the lens is obviously too slow to capture action...and you can't claim that confusion hasn't happened.

Link | Posted on May 24, 2017 at 03:38 UTC
On article Cage match: iPhone 7 Plus vs. Arri Alexa (14 comments in total)

Film Cyfrowy did a 12 camera comparison a few years ago:

BMPC 4K, BMPCC, GH4, ARRI Alexa, RED Epic/Dragon 6K, Sony F55, FS700, KineRAW Mini, Canon C500, 5D Mark III & 1DC

This is the video with the cameras labeled in the video.

https://vimeo.com/103784456

Link | Posted on May 23, 2017 at 18:46 UTC as 7th comment

"The alternative approach: on-sensor phase detection, is in its relative infancy. It may be able to make better use of existing lenses with ring-type motors, but it’s still not clear how well it can interpret significantly defocused scenes."

Gee, if only we had mirrorless cameras with on-sensor PDAF that we could evaluate...

Oh wait, we do. And Nikon has been doing on-sensor PDAF since the Nikon 1 V1...which can do pretty well with DX and FX lenses. There is debate how much the limitation to center AF for the FT-1 is a real technical limitation or a product segmentation limitation as Nikon has consistently gimped the Nikon 1 to protect their DSLR lineup.

Link | Posted on May 23, 2017 at 18:21 UTC as 66th comment | 2 replies
On article What is equivalence and why should I care? (2451 comments in total)
In reply to:

Ruekon: Thank you for this article and the effort spent to make the comparisons and answer lots of comments!

Take Nikon 1 for example: it ships with a 10-30mm f/3.5-5.6 kit lens. People come to the conclusion that picture quality doesn't catch up with larger sensor cameras. Which surprise when considering that the lens is equivalent to 27-81 f/9.5-15. Don't even people at Nikon know about this and rather tend to stop the Nikon 1 instead?

OMG years later and it's still this same confusion. It is EXACTLY in terms of "conventional exposure model" where a 50mm f2 on CX is equivalent to a 135mm f2 on FX.
Shooting a 50mm f1.4 on a CX body is EXACTLY like shooting a 50mm f1.4 on FX cropped by 2.7x.

It doesn't behave like a 135mm f5.6 because when you say something like that you end up with the kind of idiocy spouted by Tony Northrup that you cannot possibly shoot sports with the FZ200 because the lens is "equivalent to" a f16 lens and how can you possibly stop action with a F16 lens?

The DoF changes based on the crop as well but that's also a function of the crop and not because the aperture itself changed.

Link | Posted on May 23, 2017 at 18:13 UTC
On article What is equivalence and why should I care? (2451 comments in total)
In reply to:

GrahamHO: An aperture number for a lens is obtained by dividing the diameter of the lens opening into the focal length. So for example a 100 mm focal length lens with a 50 mm diameter lens opening will be 100 divided by 50 = f2. This is basic optics and is NOT dependant on sensor size. So that lens will still be f2 regardless of the sensor size. It is exactly the same as post cropping a FF image to APSC size. The resulting photo does NOT get darker.
The sensor size does NOT affect the size of the aperture. Only the APPARENT depth of field changes. ( That is the zone of the subject that APPEARS to be in sharp focus )

Again, the amount of "total light" captured is identical between the FF sensor and the crop sensor for the cropped region of interest when using the same lens.

Link | Posted on May 22, 2017 at 15:45 UTC
On article Nikon D7500: What you need to know (537 comments in total)
In reply to:

Terry Breedlove: So they cripple the D 7200 and call that an upgrade ! Does have that new 20mp sensor in it but damn Nikon come on.

About 2 stops worse...but in good light it doesn't much matter.

Link | Posted on Apr 16, 2017 at 03:53 UTC
On article Nikon D7500: What you need to know (537 comments in total)
In reply to:

Terry Breedlove: So they cripple the D 7200 and call that an upgrade ! Does have that new 20mp sensor in it but damn Nikon come on.

You only shoot wildlife in good light? I'd think you'd end up with more shots and more keepers with the D7500. If you are cropping so much that 20.9 vs 24.2 is a deal breaker and only shoot in good light I'd recommend a Nikon V3 + FT1 + 70-300 AF-P as a second body...

Link | Posted on Apr 14, 2017 at 16:50 UTC
On article Nikon D7500: What you need to know (537 comments in total)
In reply to:

endofoto: D7200 already had better sensor than D500 and better dynamic range than FF D5 (see DXO comparison I know you don't believe me), thereby D500 will sell more than D7200. I think crop sensors are rivaling FF sensors and companies are stopping this trend in order to sell FF pricy cameras. The most important thing is dynamic range for me and D7200 beats both D500 and D5, why cripple this new D7500 with D500 sensor?

@en02 The 4K crop factor on the GH4 is 2.3x. The 4K crop factor on the D7500 is...2.25x crop. With the Sigma 8mm-16mm lens the D7500 is 18mm-36mm crop equivalent 4K mode. The widest native m43 lens is the 7mm-14mm panasonic or 16.1mm-32mm on the GH4.

Only when you pair a speed booster with the 8mm-16mm can the GH4 get down to 13.1mm-26mm.

4K on the D7500 will be fine for most users at 18mm crop equivalent on the wide end if they are willing to buy the Sigma.

Link | Posted on Apr 12, 2017 at 22:15 UTC
On article Nikon D7500: What you need to know (537 comments in total)
In reply to:

endofoto: D7200 already had better sensor than D500 and better dynamic range than FF D5 (see DXO comparison I know you don't believe me), thereby D500 will sell more than D7200. I think crop sensors are rivaling FF sensors and companies are stopping this trend in order to sell FF pricy cameras. The most important thing is dynamic range for me and D7200 beats both D500 and D5, why cripple this new D7500 with D500 sensor?

Yep totally useless 4K with 2.25 crop factor...like the totally useless 4K on the GH4...granted you can use a speed booster on the GH4 but sigma does have the 10-20 and the 8-16 for a 17.4mm equivalent.

Link | Posted on Apr 12, 2017 at 12:25 UTC
On article Nikon D7500: What you need to know (537 comments in total)
In reply to:

Lightgreen: 4K in a consumer Canikon DSLR?!?! Pigs are flying...

Don't know why people are whining about the 4K crop when it's about the same as the GH4 crop. Sure the GH5 does better but video is it's claim to fame.

For video I'd rather buy a G85 but for stills and 4K this isn't a terrible option.

Link | Posted on Apr 12, 2017 at 12:12 UTC
On article What is equivalence and why should I care? (2451 comments in total)
In reply to:

wwick: Because the information on this site is always so excellent – and I assume my grasp of “equivalence” is pretty good – I was surprised to find myself confused. I don’t get how “total amount of light” on large versus small sensors is supposed to figure into the topic at hand. My guess is that it’s meant to be a non-technical way of introducing the concept of the inverse square law. If so, the graphic accompanying that discussion does not fully meet the criteria. It seems to me the relevant concept could be stated like this:

A Full Frame camera with an Equivalent FL set to an Equivalent DOF of a Micro Four Thirds camera would need 4 times more light than the smaller sensor. This would necessitate an increase in shutter speed, ISO, or the light level of the subject itself.

As to the consequences of increasing shutter speed or ISO with large versus small sensors, I’ll defer to you guys, but in terms of the basic optics, I think the article got a little more entangled than was necessary.

wwick, this is confusion because it is presented in an unnecessarily confusing way.

You can determine equivalence simply by using the same lens on both sensors and discover that when you apply the crop factor to the larger sensor (in the example above 2x) you end up with the same image in terms of exposure, field of view, noise, focal length, etc. Total light is identical because the illuminated/uncropped sensor area is identical.

The primary difference is the number of pixels because smaller sensors tend to have far higher pixel densities. Compare a 1" sensor density vs a FF sensor density.

Link | Posted on Dec 15, 2016 at 21:51 UTC
On article What is equivalence and why should I care? (2451 comments in total)
In reply to:

GrahamHO: An aperture number for a lens is obtained by dividing the diameter of the lens opening into the focal length. So for example a 100 mm focal length lens with a 50 mm diameter lens opening will be 100 divided by 50 = f2. This is basic optics and is NOT dependant on sensor size. So that lens will still be f2 regardless of the sensor size. It is exactly the same as post cropping a FF image to APSC size. The resulting photo does NOT get darker.
The sensor size does NOT affect the size of the aperture. Only the APPARENT depth of field changes. ( That is the zone of the subject that APPEARS to be in sharp focus )

Richard, or you could shoot the same 50mm lens on both sensors, crop to the same FoV of the smaller sensor and see that both are F2, provide the same angle of view and same perceptual find of view.

This is proven to be true every time someone with a FX camera shoots in DX mode and why we call these crop sensors.

Link | Posted on Dec 15, 2016 at 21:38 UTC
In reply to:

StevenE: Sad as it is, it was war. And not just any war, but a world war and an attack on American soil. The Japanese, the Germans, and the Italians were all treated this way. Espionage was a big concern.
BTW ... most people express heightened "empathy" for the woman mostly because she's young and pretty. I think the photos are important and moving, but the virtue-signalling in the comments here is not compelling.

It was racism. The Chinese were not well treated either and they were allies.

Never heard of the Chinese Exclusion Act? It took until 1943 for it to be repealed and only because the Chinese government was mad and the Japanese were merrily using it as propaganda.

Link | Posted on Dec 12, 2016 at 21:46 UTC
On article What is equivalence and why should I care? (2451 comments in total)
In reply to:

sina_hml: I know it's an old article but i hope someone can explain some of my questions.
Here is how i understand it:
I have a 5d and a 450d and a 50mm 1.8. Both cameras have identical flange distance, so the lens is producing the exact same image at the sensor plane.
450d captures a smaller part of this image. I think everyone agree with me so far.
The part i don't understand is why do some insist that the picture that 450d sees is darker than what 5d sees? it is a smaller amount of the total light that is entering the lens but it is also used to illuminate a smaller area. I assume that the amount of light that each pixel (photo cell etc.) receives is the same between the cameras.

"However, why would 600mm F15.6 ISO 3086 (if you were confident that equivalent ISOs were going to give you a close-enough answer) make you conclude that the camera is unusable in low light?"

Um...I don't. It was a comment in this thread you made 4 months ago regarding the FZ200.

"Which, as you can imagine, gives you a lot of depth-of-field but is usable in daylight, but almost unusable in low light."

Granted you say "almost" but there are many images in the Panny forum of low light shots taken with the FZ200. It can't be that hard to use and for a bridge camera appears to do reasonably well with low light.

Did I misunderstand the context of your statement and you me ant something else?

Link | Posted on May 4, 2015 at 21:18 UTC
On article What is equivalence and why should I care? (2451 comments in total)
In reply to:

sina_hml: I know it's an old article but i hope someone can explain some of my questions.
Here is how i understand it:
I have a 5d and a 450d and a 50mm 1.8. Both cameras have identical flange distance, so the lens is producing the exact same image at the sensor plane.
450d captures a smaller part of this image. I think everyone agree with me so far.
The part i don't understand is why do some insist that the picture that 450d sees is darker than what 5d sees? it is a smaller amount of the total light that is entering the lens but it is also used to illuminate a smaller area. I assume that the amount of light that each pixel (photo cell etc.) receives is the same between the cameras.

@richard "full frame sensor still performs better, thanks to simply having more sensor."

Having more sensor AND having more lens. It isn't "simply" due to larger sensor size.

The presumption that a longer lens exists for FF is not always correct. For example, while you can use the Canon 85mm f1.2 on a M43 there isn't a 170mm f1.2 lens for FF.

Or when using a 400mm f2.8 on the Nikon V3. There isn't a 1080mm f2.8 lens for your D810 to utilize the entirety of the extra sensor area. The best you can do is a 800mm f5.6.

The clearest way to describe light equivalence of crop sensors is to describe it as a crop of a FF sensor because as you state:

"If the pixels are the same size, then an APS-C crop from the full frame sensor will be identical to an APS-C image, taken with the same settings."

Describing equivalence as "600mm f15.6 ISO 3086" is convoluted and leads to the wrong conclusion...such as the camera is unusable in low light.

Link | Posted on May 4, 2015 at 19:20 UTC
On article What is equivalence and why should I care? (2451 comments in total)
In reply to:

sina_hml: I know it's an old article but i hope someone can explain some of my questions.
Here is how i understand it:
I have a 5d and a 450d and a 50mm 1.8. Both cameras have identical flange distance, so the lens is producing the exact same image at the sensor plane.
450d captures a smaller part of this image. I think everyone agree with me so far.
The part i don't understand is why do some insist that the picture that 450d sees is darker than what 5d sees? it is a smaller amount of the total light that is entering the lens but it is also used to illuminate a smaller area. I assume that the amount of light that each pixel (photo cell etc.) receives is the same between the cameras.

@richard "Panasonic FZ200 has a 4.5-108mm F2.8 lens

In full-frame terms that would be equivalent to a 25-600mm F15.6 lens.

This means 108mm, F2.8, ISO 100 on a small sensor would be the same as 600mm, F15.6, ISO 3086. Which, as you can imagine, gives you a lot of depth-of-field but is usable in daylight, but almost unusable in low light."

Would it not have been clearer to state that 108mm f2.8 on a small sensor is equivalent to 108mm f2.8 on a FF sensor cropped to a FOV of 600mm.

There are many examples of usable FZ200 images in low light. Aren't the IQ differences between a FF crop and the FZ200 images largely due to pixel size and sensor characteristics/age?

Link | Posted on May 4, 2015 at 05:46 UTC
On article What is equivalence and why should I care? (2451 comments in total)
In reply to:

sina_hml: I know it's an old article but i hope someone can explain some of my questions.
Here is how i understand it:
I have a 5d and a 450d and a 50mm 1.8. Both cameras have identical flange distance, so the lens is producing the exact same image at the sensor plane.
450d captures a smaller part of this image. I think everyone agree with me so far.
The part i don't understand is why do some insist that the picture that 450d sees is darker than what 5d sees? it is a smaller amount of the total light that is entering the lens but it is also used to illuminate a smaller area. I assume that the amount of light that each pixel (photo cell etc.) receives is the same between the cameras.

@richard "If the pixels are the same size, then an APS-C crop from the full frame sensor will be identical to an APS-C image, taken with the same settings."

Hence the name "crop sensor". The light equivalence should have been described in this way in those articles. The "total light" discussion caused even more confusion and the belief among many that what you stated above is not true.

Link | Posted on May 4, 2015 at 05:04 UTC
On article What is equivalence and why should I care? (2451 comments in total)
In reply to:

kociasek: The caption under the photograph of the four lenses seems to be wrong. It says:
"These four lenses are all 85mm equivalent F1.2s. However, this does not mean they're all 85mm F1.2 equivalent."
Unless I'm mistaken, "equivalent" should be dropped from the first sentence.

@bobn2 Not if you are already at your camera's ISO limit

@alberto Yes, it's equivalence in DoF and theoretical noise. So just state that.

Sony, 10.4-37.1mm F1.8-4.9 lens (28-100mm FoV F4.8-13.2 DoF equiv)

Noise, as seen in the provided examples, is not quite what you would expect from the numbers. Crop sensors noisier than FF sensors is a sufficiently accurate description without testing the specific models being compared.

Link | Posted on Jul 12, 2014 at 02:09 UTC
On article What is equivalence and why should I care? (2451 comments in total)
In reply to:

Louschro: What is the advantage of using a camera with a larger sensor? You can take any (!) equivalent picture, that a camera with a smaller sensor can take. But additionally there is the potential to take (non equivalent) pictures with less DOF and less noise, which cameras with smaller sensor can't take. You have decide: Is this potential so important for you, that you would accept the burden to always carry the larger and heavier system?

Very often larger sensors have more resolution. How does it affect equivalence? In this case the equivalence of noise is not given. Instead the pictures will have more noise due to the smaller pixels.

@cheng bao

I can get the shot with a 50/1.2 just fine on m43 at the same shutter speed and ISO. It'll just be more noisy but not under exposed.

Link | Posted on Jul 12, 2014 at 00:43 UTC
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