Pixel Density is GENIUS!

Started Jul 13, 2008 | Discussions
RRJackson
RRJackson Senior Member • Posts: 2,555
Pixel Density is GENIUS!

We've suffered at the hands of the "Megapixel Race" for years now. Every time some useful camera is introduced it seems to get phased-out in a few months and replaced with a version just like it only with a higher megapixel count, which effectively renders the camera less useful. Go try to find a deal on a used F31fd if you have any doubts about whether or not people actually want cameras with less "Pixel Density."

If the public at large catch on to the concept of pixel density it means the manufacturers will be prompted to build cameras catering to a "Pixel Density Race" and everyone wins.

There's no good reason why a person with a 5-6 megapixel compact shouldn't be able to shoot photos in the same range of conditions that a guy with a D3 can shoot today. Make the sensors bigger and drop the megapixel count until the average person can shoot snapshots at dimly-lit family gatherings without tragic results. 95% of the people who take photographs probably won't ever see them larger than 4x6, anyway. Those people will be much better served by latitude and high-ISO sensitivity than by enough resolution to print a 16x20 at 300 dpi.

And it's a handy metric for more experienced photographers, as well, since it gives a clear indication as to how small the photosites have been made to yield a 24-megapixel sensor (or whatever the next goalpost turns out to be).

Give Phil and Phriends props for a great idea.

Andrew dB Contributing Member • Posts: 970
No really, it isn't

RRJackson wrote:

We've suffered at the hands of the "Megapixel Race" for years now.
Every time some useful camera is introduced it seems to get
phased-out in a few months and replaced with a version just like it
only with a higher megapixel count, which effectively renders the
camera less useful. Go try to find a deal on a used F31fd if you have
any doubts about whether or not people actually want cameras with
less "Pixel Density."

I agree with you that the advent of higher MP cameras (particularly compacts) has brought along with it massively overdone noise reduction which to me looks hideous. I was very glad to find that the CHDK hack allows me to get unprocessed raw files from my little Ixus 70 and even without any NR, they look far better than the somewhat overprocessed in camera JPEGs. If only all compacts had that option.

If you want to blame anything, it's probably down to cost cutting which means that software NR is cheaper than high quality read stages combined with pixel peeping reviewers who would pointlessly view images at 100% and whinge about pixel level noise while ignoring overall image noise.

If the public at large catch on to the concept of pixel density it
means the manufacturers will be prompted to build cameras catering to
a "Pixel Density Race" and everyone wins.

Good luck with that.

There's no good reason why a person with a 5-6 megapixel compact
shouldn't be able to shoot photos in the same range of conditions
that a guy with a D3 can shoot today. Make the sensors bigger and
drop the megapixel count until the average person can shoot snapshots
at dimly-lit family gatherings without tragic results. 95% of the
people who take photographs probably won't ever see them larger than
4x6, anyway. Those people will be much better served by latitude and
high-ISO sensitivity than by enough resolution to print a 16x20 at
300 dpi.

The day you see a 5-6MP compact with a sensor the size of that in the D3 (which is what you would need to get the performance you want) is the day hell freezes over! No-one would pay the massive pricetag for what would inevitably be a very large 'compact' if it had a zoom of any useful range.

95% of the camera buying public really don't care. If they get a picture at all that they can email to a friend/put on Facebook/print to 4x6 then they're pleased. it's only a tiny proportion of camera nuts who know what the technology could do and they still enjoy the benefits of cheap, tiny cameras that deliver good enough image quality (particularly if you know how to process them)

And it's a handy metric for more experienced photographers, as well,
since it gives a clear indication as to how small the photosites have
been made to yield a 24-megapixel sensor (or whatever the next
goalpost turns out to be).

Give Phil and Phriends props for a great idea.

It's a worthless metric that has no basis in science. Outside of very specialised fields such as astrophotography, I've never heard of pixel pitch having any real significance to the photographer.

Sensor size, on the other hand is absolutely worth emphasising.

BIJ001 Veteran Member • Posts: 5,649
Re: Pixel Density is GENIUS!

RRJackson wrote:

We've suffered at the hands of the "Megapixel Race" for years now.
Every time some useful camera is introduced it seems to get
phased-out in a few months and replaced with a version just like it
only with a higher megapixel count, which effectively renders the
camera less useful.

That is why cameras get worse and worse all the time.

For example I have an old HP 735. It drains the batteries very fast, it is slow to record the image onto the card etc. It has 3 Mpix.

I later bought a Canon A610 which is a charm to use: it is much faster during operation, it is much, much faster to write the image onto the card, it has much more options to set. And hey, it is 5 Mpix instead of 3!

It is a pity cameras get worse and worse all the time.

 BIJ001's gear list:BIJ001's gear list
Canon PowerShot G11
RRJackson
OP RRJackson Senior Member • Posts: 2,555
Re: No really, it isn't

Andrew dB wrote:

The day you see a 5-6MP compact with a sensor the size of that in the
D3 (which is what you would need to get the performance you want

The D3 is a 12 megapixel 135-sensor camera. A compact 5 megapixel camera with a 2/3" sensor could have close to the same photosite size.

simpy Veteran Member • Posts: 3,090
Re: No really, it isn't

RRJackson wrote:

The D3 is a 12 megapixel 135-sensor camera. A compact 5 megapixel
camera with a 2/3" sensor could have close to the same photosite size.

Err.. I think your math is a little off here. The D3 has a sensor area that is approx. 16 times larger than a 2/3" sensor. The 5MP compact sensor therefore corresponds to an approx. 80MP 135 format sensor.

Simon

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RRJackson
OP RRJackson Senior Member • Posts: 2,555
Re: No really, it isn't

simpy wrote:

RRJackson wrote:

The D3 is a 12 megapixel 135-sensor camera. A compact 5 megapixel
camera with a 2/3" sensor could have close to the same photosite size.

Err.. I think your math is a little off here. The D3 has a sensor
area that is approx. 16 times larger than a 2/3" sensor. The 5MP
compact sensor therefore corresponds to an approx. 80MP 135 format
sensor.

Eh, it was actually off the top of my head.

24mm x 36mm / 2.5 ~ 10mm x 14mm. That's actually closer to the range of 1" sensors than 2/3" sensors, but my point was that a reasonably sized sensor with a much lower pixel count should be able to perform nearly as well as the high-end of current DSLRs, which are just now starting to have low light and latitude performance that's truly useful.

Dejan Malikovski Senior Member • Posts: 1,611
Digicams with 1.5x crop factor

They could make a digicam with a big sensor appx 1.5x or 2x crop factor with reasonable amount of pixels 6-8. Base iso of 100 and real iso 3200 faked 6400. No viewfinder, just live view. No tilt, swivel 2.5" screen. Popup flash (high DSLR style) and not integrated (in-body). Hot shoe. Dedicated/Shared buttons like D80 or 40D. High quality lens:
1. Fixed focal length (effective) 35mm f/1.8 or
2. Vari zoom (effective) 26-100mm f/2.0-2.8 (Like the old Oly's)

Grip that is no bigger than the lens sticks out of the body. The lens should not be retractable. With real zoom ring, not on buttons.

Fancy power saver mode that stand-by like a dslr. A optical viewfinder (included) very BIG (!!!) and LARGE and BRIGHT, that has no zoom and attaches to the hot-shoe, like the sigma. If the lens is zoom then viewfinder should have rectangles on 50mm 70mm and 100mm to give a rough idea of what the camera is seeing.
Instant power up. Instant shooting.
Well, where is it?
--

How many megapixels you need from a camera:
http://www.bhphotovideo.com/FrameWork/charts/resolutionChartPopup.html

RRJackson
OP RRJackson Senior Member • Posts: 2,555
Re: Pixel Density is GENIUS!

The problem isn't that write speeds are slowing down or that processors are getting slower, because obviously they've improved a lot. The problem is that companies keep releasing 10 and 12 (and in Sony's case close to 14) megapixel cameras with 1/1.7’’ and 1/2.3" sensors. This metric makes it easy to see at a glance that the Sony DSC-W300 has a pixel density of 36 MP/cm² where a Fuji F31D had a pixel density of 14 MP/cm². This isn't something that might be as glaringly apparent if it wasn't a searchable metric.

BIJ001 wrote:

That is why cameras get worse and worse all the time.

For example I have an old HP 735. It drains the batteries very fast,
it is slow to record the image onto the card etc. It has 3 Mpix.

I later bought a Canon A610 which is a charm to use: it is much
faster during operation, it is much, much faster to write the image
onto the card, it has much more options to set. And hey, it is 5 Mpix
instead of 3!

It is a pity cameras get worse and worse all the time.

RRJackson
OP RRJackson Senior Member • Posts: 2,555
Re: Digicams with 1.5x crop factor

Dejan Malikovski wrote:

They could make a digicam with a big sensor appx 1.5x or 2x crop
factor with reasonable amount of pixels 6-8.

A 6-megapixel 4/3 compact with two or three teeny little primes would be pretty sweet. I've mentioned this before, but the old Pentax 110 SLR was about the right size for this kind of stuff, IMO. No good reason the digital equivalent of this couldn't exist.

http://flickr.com/photos/98922823@N00/2367222218/

ejmartin Veteran Member • Posts: 6,274
Re: No really, it isn't

RRJackson wrote:

simpy wrote:

RRJackson wrote:

The D3 is a 12 megapixel 135-sensor camera. A compact 5 megapixel
camera with a 2/3" sensor could have close to the same photosite size.

Err.. I think your math is a little off here. The D3 has a sensor
area that is approx. 16 times larger than a 2/3" sensor. The 5MP
compact sensor therefore corresponds to an approx. 80MP 135 format
sensor.

Eh, it was actually off the top of my head.

24mm x 36mm / 2.5 ~ 10mm x 14mm. That's actually closer to the range
of 1" sensors than 2/3" sensors, but my point was that a reasonably
sized sensor with a much lower pixel count should be able to perform
nearly as well as the high-end of current DSLRs, which are just now
starting to have low light and latitude performance that's truly
useful.

Better stop doing math off the top of your head. If you're going to reduce the full frame sensor by a factor 2.5 in each direction, then the area reduces by 2.5x2.5=6.25, and now you only get a little less than 2MP of those big fat D3 photosites.

-- hide signature --
RRJackson
OP RRJackson Senior Member • Posts: 2,555
Re: No really, it isn't

ejmartin wrote:

Better stop doing math off the top of your head. If you're going to
reduce the full frame sensor by a factor 2.5 in each direction, then
the area reduces by 2.5x2.5=6.25, and now you only get a little less
than 2MP of those big fat D3 photosites.

A 1" CCD is usually 9.6mm x 12.8mm, which is a much smaller sensor than the D3 sensor, but that's still a pretty big sensor. Even the 2/3" 8-megapixel sensor on the old Olympus C-8080 was only dealing with a pixel density of 14 MP/cm². I'm fairly confident that a modern 5-megapixel 1" sensor could provide a far superior image to something like the current 10-13 megapixel 1/1.7’’ sensors, which was the point I was trying to make, albeit with a math background that took Medical Ethics instead of Stats on a Dyscalculia disability waiver in film school.

Morbius Contributing Member • Posts: 674
Re: No really, it isn't

Andrew dB wrote:

95% of the camera buying public really don't care. If they get a
picture at all that they can email to a friend/put on Facebook/print
to 4x6 then they're pleased. it's only a tiny proportion of camera
nuts who know what the technology could do and they still enjoy the
benefits of cheap, tiny cameras that deliver good enough image
quality (particularly if you know how to process them)

True. And why the public care? For most people a photo is a memory captured. If it looks ok, it's fine. People on this forum obsess about details of images and equipment that mean nothing to others who don't share a passion for photography. Many who comment on this (and not you by the way) adopt a condescending tone as if being satisfied with a nice 4 x 6 with a bit of noise or slightly overdone flash or Aunt Mary's legs cut off awkwardly and a hectic background was a personal failing.

RRJackson
OP RRJackson Senior Member • Posts: 2,555
Re: No really, it isn't

Morbius wrote:

True. And why the public care? For most people a photo is a memory
captured. If it looks ok, it's fine. People on this forum obsess
about details of images and equipment that mean nothing to others who
don't share a passion for photography. Many who comment on this (and
not you by the way) adopt a condescending tone as if being satisfied
with a nice 4 x 6 with a bit of noise or slightly overdone flash or
Aunt Mary's legs cut off awkwardly and a hectic background was a
personal failing.

Most people would be overjoyed with a 3-megapixel cell phone camera if the images weren't always noisy and if the highlights didn't blow out and the shadows weren't always crushed. Of course, they wouldn't describe it that way. They'd just say, "It takes good pictures."

The formula seems kinda simple, really. I know there are engineers hovering who'll probably be happy to tell me what points I'm being retarded about (heh...and I don't mind), but the basic formula seems kinda simple. In-between chip size. Even 2/3" would probably be OK, but 1" would probably be a lot nicer. That way using a fast lens doesn't make the DOF so shallow that the average consumer autofocus system can't deliver a high percentage of keepers. Relatively low megapixel count to maintain as much low-light ability as possible. The aforementioned fast lens. Something around f/1.8 or f/2 would be peachy in a fixed lens. Something with around the same field of view as a 35-40mm lens on 135 would be ideal, IMO. An f/2.8 2x - 3x zoom for people who can't live without a zoom. Something with a low enough zoom ratio that the optics don't have to suck. Auto-ISO so Ma and Pa Kettle don't have to take photography classes. RAW capability for people who want to use it. Seems like you'd sell as many of 'em as you could build.

Which is why the DP1 is such a mystery to me. First off, they knew up-front that Foveon chips aren't exactly aces at high ISO and intead of putting a fast little lens on it they put a 16mm f/4 lens on it. If you've got one lens to work with you want a 28mm equivalent lens? At f/4? With that 1.7x crop they couldn't have more easily put a 20mm or 24mm f/2.8 ( 35mm or 40mm effective) on it and bought themselves another usable stop? Asking for f/2 would probably jack up the size and price even more, but two stops of improvement would be a pretty huge deal.

This stuff is all just starting to get useful. I don't doubt that the next five years will see a lot of great product introductions, but we seem to be in kind of a threshold period where the majors are all just starting to stick their heads up out of the trenches and consider releasing cameras that aren't slightly improved versions of the same stuff they sold last year. I hope we start seeing a real variety of options, maybe some new concepts will surface at Photokina.

I haven't bought a compact in years, but if I bought one today I'm not sure what I'd get. A DP1? For $700 with a slow wide-angle lens? A ginourmous G9, even though it feels really well-built? Probably an F40fd. even though the lens is really slow. Some friends asked me what to buy in a compact a few months ago and I suggested one. I've spent some time playing with it and it seems nice enough, but a lot nicer options should be out there. And I'll probably keep whining until they are.

FWIW, it really seems like we should be right on the verge of a real renaissance in photographic tools. I'm just impatient.

simpy Veteran Member • Posts: 3,090
Re: No really, it isn't

RRJackson wrote:

Eh, it was actually off the top of my head.

24mm x 36mm / 2.5 ~ 10mm x 14mm. That's actually closer to the range
of 1" sensors than 2/3" sensors,

I presume you divided by 2.5 to get from 12MP to approx 5MP. However, the pixel count scales with the surface area, which goes as the square of the length. A factor 2.5 in length lowers the pixel count (at the same pixel size) by a factor 2.5*2.5=6.25. Cutting down the 12MP D3 to 10x14mm gets you a 2MP camera.

Simon

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simpy Veteran Member • Posts: 3,090
Re: Pixel Density is GENIUS!

RRJackson wrote:

This metric makes it easy to see at a glance that the Sony
DSC-W300 has a pixel density of 36 MP/cm² where a Fuji F31D had a
pixel density of 14 MP/cm². This isn't something that might be as
glaringly apparent if it wasn't a searchable metric.

It would be much preferred if that searchable metric was the sensor surface area in cm². It has the benefit of actually having importance for photographs that are not inspected at 100%.

Simon

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RRJackson
OP RRJackson Senior Member • Posts: 2,555
Re: Pixel Density is GENIUS!

simpy wrote:

It would be much preferred if that searchable metric was the sensor
surface area in cm². It has the benefit of actually having importance
for photographs that are not inspected at 100%.

You can scale to reduce apparent noise if the image is on the borderline of acceptable capture, but that's not going to help you if the camera can't pull out a reasonable image in the first place. Or if the image captured was so smeared by noise reduction that it will still look like an impressionist painting even if you reduce its size to a quarter the native rez.

simpy Veteran Member • Posts: 3,090
Re: Pixel Density is GENIUS!

RRJackson wrote:

simpy wrote:

It would be much preferred if that searchable metric was the sensor
surface area in cm². It has the benefit of actually having importance
for photographs that are not inspected at 100%.

You can scale to reduce apparent noise if the image is on the
borderline of acceptable capture, but that's not going to help you if
the camera can't pull out a reasonable image in the first place. Or
if the image captured was so smeared by noise reduction that it will
still look like an impressionist painting even if you reduce its size
to a quarter the native rez.

I have two answers to that:

1) If you reduce the size enough (like for a 4x6" print), the processing artifacts will disappear.

2) Overactive noise reduction algorithms are not inherently linked to pixel density. In fact, it's mostly because people - and review sites such as this one - insist on evaluating noise at 100% that this excessive noise reduction is there.

Again, why would pixel density be better than a simple sensor size?

Simon

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RRJackson
OP RRJackson Senior Member • Posts: 2,555
Re: Pixel Density is GENIUS!

simpy wrote:

Again, why would pixel density be better than a simple sensor size?

But DP lists both. Are you upset that they're giving you too many searchable options?

Andrew dB Contributing Member • Posts: 970
Re: No really, it isn't

RRJackson wrote:

ejmartin wrote:

Better stop doing math off the top of your head. If you're going to
reduce the full frame sensor by a factor 2.5 in each direction, then
the area reduces by 2.5x2.5=6.25, and now you only get a little less
than 2MP of those big fat D3 photosites.

A 1" CCD is usually 9.6mm x 12.8mm, which is a much smaller sensor
than the D3 sensor, but that's still a pretty big sensor. Even the
2/3" 8-megapixel sensor on the old Olympus C-8080 was only dealing
with a pixel density of 14 MP/cm². I'm fairly confident that a modern
5-megapixel 1" sensor could provide a far superior image to something
like the current 10-13 megapixel 1/1.7’’ sensors, which was the point
I was trying to make, albeit with a math background that took Medical
Ethics instead of Stats on a Dyscalculia disability waiver in film
school.

A compact with a decent sized sensor would be pretty nice. Even a 2/3 chip would be a big improvement but provided the pixel count isn't so high as to make the camera unattractively slow, we don't need to worry about pixel density.

The limiting factor on a hypothetical 20MP compact with a 2/3 sensor isn't image noise, it's that file sizes would be large and the camera might be a bit slow for the market it's being targeted at.

It would be better for DPR to try and educate buyers on the tradeoffs involved with buying a small sensor camera rather than getting bogged down in the complexity of pixel density estimates that are only tangentially related to overall image quality.

RRJackson
OP RRJackson Senior Member • Posts: 2,555
Re: No really, it isn't

simpy wrote:

I presume you divided by 2.5 to get from 12MP to approx 5MP. However,
the pixel count scales with the surface area, which goes as the
square of the length.

Yeah, didn't occur to me until after I'd posted. Math is not intuitive for me. Still, it seems like an argument could be made for bigger sensors, bigger photosites even at the expense of resolution. Although some digiicams seem to be binning now. I assume that's why I keep seeing low-resolution/High-ISO modes popping up.

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