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Megapixels. They even keep growing
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PostPosted: Thu Sep 18, 2014 10:07 am    Post subject: Megapixels. They even keep growing Reply with quote

Hi all,

I wanted to discuss with you why you think the megapixel count is increasing over the years. As the sensor size remains the same one expect that by just increasing the resolution the captured image would be more noisy.

I had a look on images from older cameras like the nikon d700 that, If I am not wrong it was 12mp camera, and their iso at 3200 or 6400 is much better even compared to todays cameras.

I am shooting with a 16 megapixel camera and I would be happy to even shoot at 12 or 8 Mpixels if there was way to give me less noise per capture.

I wonder though why the trend instead of producing less noisy captures is pushing the number of megapixels to grow. Why I can not have today a low noise 12 Mpixels APS-C or FF frame?

I understand that the megapixel count can put a limit to print sizes, but for my work, 12 or even 8 Mpixels would be more than enough.

I am waiting for your feedback for a nice discussion.

Bring coffee

Alex


PostPosted: Thu Sep 18, 2014 12:18 pm    Post subject: Reply with quote

Alex wrote:
Why I can not have today a low noise 12 Mpixels APS-C or FF frame?

phone and tablet have already a resolution higher than HD, 4K camera and tv are slowly become the new standard, next step will be the 8K (up to 67Mpixels)
when I got my HD lcd, most of my 400D 'keeper' start to look poor, I expect the same for my 5DII pics when I will switch to a 4K lcd
in summary, as long as you stay with your cheap HD ready or analog monitor, you can stay with your 12 Mpixels cam
some year ago, I used to scan photo at 640x480 who was much higher than PAL television

Quote:
I would be happy to even shoot at 12 or 8 Mpixels if there was way to give me less noise per capture

you are right, most high Mpixels have to use tricks to give acceptable quality, newer cpu like the sony BIONZ adapt noise reduction depending content and even try to limit diffraction of small sensor with software
welcome artifacts and washed pics, but marketing will always be the king


PostPosted: Thu Sep 18, 2014 12:29 pm    Post subject: Reply with quote

Ok you have not seen the Sony A7s then
12mpx Full frame with excellent noise


Its like cars more BHP sells faster cars but if you want acceleration look at Torque rather than BHP as a car that as 500bhp and say 300lbs of torqe vs a 350bhp car and 500lbs of torque everyone would say that the 500bhp must be better.


PostPosted: Thu Sep 18, 2014 4:02 pm    Post subject: Reply with quote

The megapixel race began when digital sensors had less resolution then the film in the same format. It was a legitimate race then. The goal was to be able to use your digital camera as you did with the film camera and have the same (if not greater) enlargements starting from the same format. It was a part of the film-digital debate in the years when digital was struggling to replace film, therefor I think it was legitimate. But, from the resolution point of view, the battle is over and the digital army won. Film is now only used by enthusiasts in search of a distinct view.

But that battle was not only film-digital, it was a battle between digital camera manufacturers, too. And a new category of "mercenaries of the digital army" appeared - the pixel peepers.
The megapixel race of today is this second battle continued. But now it is a distorted, meaningless battle most of the time. It is no more directly related with how much one needs to print his/her photos. Is a race for higher resolution "per se", maintained by the camera manufacturers with the help of the "pixel peepers army". Why? To sell you and me a new camera every year saying that it's better than the previous one because it has more megapixels. In fact, very few people really need more megapixels because of the big prints they have to make, as you pointed out. If the camera manufacturers would rely only on them the'll go bankrupt.

The great majority of buyers don't buy a camera related to how big they need to print. They've been induced the idea that, generally, more megapixels = better camera and they want and buy better cameras, without deeper thinking of what is better for the new camera. The development of more and more megapixels cameras didn't increase the big prints demand. By the contrary, the demand for prints decreased compared with the film era. This is a clear sign of a distorted tendency.

IMO, as usually, the companies increase their profits by inducing false needs to the medium consumers.


Last edited by dan_ on Thu Sep 18, 2014 4:50 pm; edited 2 times in total


PostPosted: Thu Sep 18, 2014 4:20 pm    Post subject: Reply with quote

More pixels will need a faster computer for processing the photos, bigger monitor with higher resolution for display, faster and larger storage, and sharper lenses to feed the sensor. Wink


PostPosted: Thu Sep 18, 2014 5:42 pm    Post subject: Reply with quote

Im okay with 8, 10, 12 and 14 megapixels, cannot see much difference between the 8 and 10 and not that huge a difference in the 14 over the 10


PostPosted: Thu Sep 18, 2014 7:28 pm    Post subject: Reply with quote

calvin83 wrote:
More pixels will need a faster computer for processing the photos, bigger monitor with higher resolution for display, faster and larger storage, and sharper lenses to feed the sensor. Wink


I noticed that when I got my Nikon D3200, I've not used it for a while and have been using a PentaxK10d with 10mp mainly then when I got the Sony A6000 I noticed it again.


PostPosted: Thu Sep 18, 2014 8:54 pm    Post subject: Re: Megapixels. They even keep growing Reply with quote

alaios wrote:
As the sensor size remains the same one expect that by just increasing the resolution the captured image would be more noisy.


Why do you think that ?

Quote:
I had a look on images from older cameras like the nikon d700 that, If I am not wrong it was 12mp camera, and their iso at 3200 or 6400 is much better even compared to todays cameras.


Do you have two pictures, one taken with the D700 and one with the D800, with everything else unchanged ? Have you visited DxOMark and compared the signal-to-noise ratios for the D700 and the D800 ?


PostPosted: Thu Sep 18, 2014 11:11 pm    Post subject: Re: Megapixels. They even keep growing Reply with quote

sichko wrote:
alaios wrote:
As the sensor size remains the same one expect that by just increasing the resolution the captured image would be more noisy.


Why do you think that ?

Quote:
I had a look on images from older cameras like the nikon d700 that, If I am not wrong it was 12mp camera, and their iso at 3200 or 6400 is much better even compared to todays cameras.


Do you have two pictures, one taken with the D700 and one with the D800, with everything else unchanged ? Have you visited DxOMark and compared the signal-to-noise ratios for the D700 and the D800 ?


Ignore these theorists that talk a lot and never show pictures....

Saying you want a digital sensor with no noise is like saying you want a film with no grain - asking for the impossible, even the finest grained films like Agfa Copex and Kodak Tech Pan still have visible grain when enlarged.

At base ISO, most APS-C and FF cameras of the last 5-6 years have so little noise, it's just not an issue.

Also, there are superb noise reduction software now such as Dfine.

In practical terms, any modern APS-C or FF camera, used on the lowest three ISO settings will not present any noise issues if you expose the image correctly. Noise will appear in shadow areas if you lighten them a lot due to underexposure, then you can turn to a program like Dfine to get rid of most of it.


PostPosted: Thu Sep 18, 2014 11:18 pm    Post subject: Reply with quote

Hi,
what I have found is that by increasing the megapixels you increase resolution at base iso. It is a trade off, if you reduce pixel count resolution at low isos falls but increases (compared with a higher megapixel camera) in high isos.

The questions though is
-How much megapixels you need? This somehoe relates with print sizes. So to simplify further the question what print sizes (A4,A3,A2) a 6Mpixel image can give? a 12?16?24? and so on. If I know that not any customer would ever ask for sizes up to A3 it would be nice to have the options (through market products) to pick the megapixel count that can cover your print sizes you want and trade the rest with improved low light quality

-I do nopt have a d700 or d800. I looked on dxomarks some time ago but to be honest, even though I am coming from an electrical engineering background, I do not care much for the numerology. Every time I look a shot is not the bad iso performace for sure (with minor exceptions). I do not think that photographers one decade ago they were filling that 12Mpixels were not enough.

Thanks for sharing your thoughts


PostPosted: Fri Sep 19, 2014 8:43 am    Post subject: Reply with quote

I am ok with 5D classic, 12Mpx, that's about the limit.
Largest I need is 30x60cm / 12"x24" photo book.
More Mpx allows me to crop a bit when print in 12x24".
The book is for viewing in close range and cover the eye field.

Older bodies with 6Mpx is too limited, but still able to cover 12x12" with enough details.


PostPosted: Fri Sep 19, 2014 11:55 am    Post subject: Reply with quote

I agree, 12mp is enough for most uses. I have had 20x30" prints made from 14mp files and they look good.


PostPosted: Fri Sep 19, 2014 12:05 pm    Post subject: Reply with quote

16MP full-color RGB sensor is enough for me. Wink


PostPosted: Fri Sep 19, 2014 12:18 pm    Post subject: Reply with quote

When I was in high school, I was told in the locker room that bigger is always better. I haven't not seen evidence contradicting that claim.

Laughing Laughing Laughing Laughing Laughing Laughing Laughing Laughing Laughing Laughing Laughing Laughing Laughing Laughing Laughing Laughing Laughing Laughing Laughing


PostPosted: Fri Sep 19, 2014 1:12 pm    Post subject: Reply with quote

alaios wrote:
-I do nopt have a d700 or d800.


Neither do I - too expensive for me. But you did mention the D700 and you seemed to think that more modern cameras, with more pixels, might be noisier. Since neither of us have these two cameras we have to rely on other peoples observations. Some people have compared the D700 and the D800. And guess what ! The D800 wins - in their estimation. Of course it's more expensive and file-handling is more difficult. But for some people the difference in picture quality is worth it. I can give you a link if you wish.

The D800 represents an arbitrary choice for comparison. You could choose the Canon 5D MKIII - or something else.

Quote:
I looked on dxomarks some time ago but to be honest, even though I am coming from an electrical engineering background, I do not care much for the numerology.


If you have a background in electrical engineering I suspect that you have an advantage over most of us. You are well placed to look at the methodology and the results and to make up your own mind. Although expertise and independent thought are not always appreciated on this forum.


PostPosted: Mon Sep 22, 2014 12:52 pm    Post subject: Re: Megapixels. They even keep growing Reply with quote

iangreenhalgh1 wrote:
sichko wrote:
alaios wrote:
As the sensor size remains the same one expect that by just increasing the resolution the captured image would be more noisy.


Why do you think that ?

Quote:
I had a look on images from older cameras like the nikon d700 that, If I am not wrong it was 12mp camera, and their iso at 3200 or 6400 is much better even compared to todays cameras.


Do you have two pictures, one taken with the D700 and one with the D800, with everything else unchanged ? Have you visited DxOMark and compared the signal-to-noise ratios for the D700 and the D800 ?


Ignore these theorists that talk a lot and never show pictures....


The OP didn't ask for pictures. He wanted a "nice discussion". Is trying to inhibit someone else from speaking your idea of a "discussion" ? It's certainly not "nice". What are you afraid of ?

Quote:
Saying you want a digital sensor with no noise is like saying you want a film with no grain - asking for the impossible, even the finest grained films like Agfa Copex and Kodak Tech Pan still have visible grain when enlarged.


What does film grain have to do with sensor noise ?

Quote:
At base ISO, most APS-C and FF cameras of the last 5-6 years have so little noise, it's just not an issue.


Not everyone thinks so. I can provide links if you wish.

Quote:
Also, there are superb noise reduction software now such as Dfine.


Noise reduction can remove detail. Noise destroys information. Some people would prefer to have as little as possible.

Quote:
In practical terms, any modern APS-C or FF camera, used on the lowest three ISO settings will not present any noise issues if you expose the image correctly.


It's certainly a good idea to collect as much light as possible. However, this might be limited by (i) scene illumination, (ii) the need for a fast shutter, to freeze motion for example, and (iii) a (relatively) small aperture needed for optimum lens peformance and/or DOF. In these circumstances it might be better to use a higher ISO setting rather than a lower one. It will depend upon the individual camera. I can give an illustration if you wish.


PostPosted: Mon Sep 22, 2014 11:48 pm    Post subject: Reply with quote

A curious reaction against the increase of the number of pixels is occurring today. A common argument is that the greater the number of pixels, the lower the signal /noise ratio. I think this is just a misunderstanding of the problem.

It is true that when the number of pixels of a sensor increases, the area of each photosite decreases and so the signal-to-noise ratio per pixel decreases. However, the signal-to-noise ratio per the area remains the same! This conclusion is valid if the read noise is negligible, what effectively happens in practice, as Roger N. Clark pointed out:

"It turns out that the noise making up the majority of images we view from good modern digital cameras is dominated by photon counting statistics, not other sources. So to make an image with a high signal-to-noise ratio, one must collect the most photons possible."

The trend in increasing the number of pixels is good, in my opinion. The tests I conducted showed that it takes more than 400 Mpixel to fully exploit the resolution in the center of field of a lens like the Helios 44M-4, which is a good lens but certainly not the best. A sensor with 1 Gpixel would be necessary to exploit all the resolution of the best modern lenses.

With the current technology it is perfectly possible to produce a full-frame sensor with 1/2 billiom pixels. Consider, for example, the 16 Mpixel sensor used in the Panasonic FZ70. The FZ70 sensor has dimensions of 6.17x4.55mm, which means that a 500 Mpixels FF sensor with the same pixel pitch could be made. Why then comercial 500 Mpixel sensors are not being produced?

The answer lies basically in the difficulty to quickly process the enormous amount of data that a sensor this size would produce. Each captured image would possibly take 20-30 seconds to be recorded in the memory, what would not be acceptable by most photographers. Nonetheless, as digital circuits become faster and faster, it is expected that multi-giga pixel sensors will become viable in a few years.

A good photograph doesn't usually need so much resolution for stunning visual impact. What would be the utility of an ultra high-resolution image capture? Among other possibilities, one can think of implementing a digital zoom of high quality. For example, it would be possible to implement an equivalent a 25-100mm F1.4 lens from a modern 25mm F1.4 prime lens used together a FF camera with 1 Gpixel sensor. That camera would be compact and light, with few mechanical parts. And if desired, the zoom factor could be decided after the photo was taken!


PostPosted: Tue Sep 23, 2014 2:08 am    Post subject: Reply with quote

Gerald wrote:
... With the current technology it is perfectly possible to produce a full-frame sensor with 1/2 billiom pixels. Consider, for example, the 16 Mpixel sensor used in the Panasonic FZ70. The FZ70 sensor has dimensions of 6.17x4.55mm, which means that a 500 Mpixels FF sensor with the same pixel pitch could be made. Why then comercial 500 Mpixel sensors are not being produced?

The answer lies basically in the difficulty to quickly process the enormous amount of data that a sensor this size would produce. Each captured image would possibly take 20-30 seconds to be recorded in the memory, what would not be acceptable by most photographers. Nonetheless, as digital circuits become faster and faster, it is expected that multi-giga pixel sensors will become viable in a few years.

...


Parallel processing methods will make data transfer fast enough. Wink

Large dense chips are not economical to make due to very large reject rate -- many many chips must be made to find a good one...


PostPosted: Tue Sep 23, 2014 12:15 pm    Post subject: Reply with quote

Yes, parallel processing can be very fast but spends a lot of energy. The battery of the camera would have to be several times larger than is today, and the amount of heat generated would destroy the electronic circuitry.

The rejection rate is basically related to the area, not the density of the circuits. The fabrication of current FF sensors have reached na acceptable rate of rejection. I do not believe that increasing the density of the circuit would increase the rate of rejection to the point of making the manufactruing economically unviable.

An attempt to predict, assuming that the density of FF sensors will double every two years:

2015: 50 Mpixels
2017: 100 Mpixels
2019: 200 Mpixels
2021: 400 Mpixels
2023: 800 Mpixels
2024: 1 Gpixels


PostPosted: Tue Sep 23, 2014 4:59 pm    Post subject: Reply with quote

Gerald wrote:
Yes, parallel processing can be very fast but spends a lot of energy. The battery of the camera would have to be several times larger than is today, and the amount of heat generated would destroy the electronic circuitry.

The rejection rate is basically related to the area, not the density of the circuits. The fabrication of current FF sensors have reached na acceptable rate of rejection. I do not believe that increasing the density of the circuit would increase the rate of rejection to the point of making the manufactruing economically unviable.

An attempt to predict, assuming that the density of FF sensors will double every two years:

2015: 50 Mpixels
2017: 100 Mpixels
2019: 200 Mpixels
2021: 400 Mpixels
2023: 800 Mpixels
2024: 1 Gpixels


Electronics Engineers beg to differ. Believe whatever you like; the physics indicate otherwise, which is why the prediction is wildly inaccurate imho.


PostPosted: Tue Sep 23, 2014 6:24 pm    Post subject: Reply with quote

Gerald wrote:

The trend in increasing the number of pixels is good, in my opinion. The tests I conducted showed that it takes more than 400 Mpixel to fully exploit the resolution in the center of field of a lens like the Helios 44M-4, which is a good lens but certainly not the best. A sensor with 1 Gpixel would be necessary to exploit all the resolution of the best modern lenses.


Very interesting! Have you described your test anywhere? If not, could you give use a brief summary? It would be greatly appreciated!

Cheers,
Lou


PostPosted: Tue Sep 23, 2014 6:37 pm    Post subject: Reply with quote

lm4187 wrote:
Gerald wrote:

The trend in increasing the number of pixels is good, in my opinion. The tests I conducted showed that it takes more than 400 Mpixel to fully exploit the resolution in the center of field of a lens like the Helios 44M-4, which is a good lens but certainly not the best. A sensor with 1 Gpixel would be necessary to exploit all the resolution of the best modern lenses.


Very interesting! Have you described your test anywhere? If not, could you give use a brief summary? It would be greatly appreciated!

Cheers,
Lou


The test is described here:
http://forum.mflenses.com/the-amazingly-high-resolution-of-a-helios-44m-4-t65636,highlight,%2Bamazingly.html

Sadly, the pictures are gone after the forum server crashed, but I hope you can understand what I said there.


PostPosted: Tue Sep 23, 2014 7:43 pm    Post subject: Reply with quote

Gerald wrote:
An attempt to predict, assuming that the density of FF sensors will double every two years:
2015: 50 Mpixels
2017: 100 Mpixels
2019: 200 Mpixels
2021: 400 Mpixels
2023: 800 Mpixels
2024: 1 Gpixels


The Zeiss Biogon resolve 400lp/mm, about 130 Mpixels
camera with more Mpixels than that are worthless because 400lp/mm is the limit of diffraction
even if the Biogon could have a resolution of 800lp/mm, physics wouldn't allow to record it


Zeiss wrote:

we used a ZM-Biogon 25 in a recent test to determine maximum resolving power. The high resolution film of choice was the SPUR Orthopan UR supplied and processed by SPUR.

The result was a whopping 400 lp/mm on film, recorded with the Biogon 25 at f/4 in the center of the image.
This value, 400 lp/mm, corresponds to the maximum resolution theoretically possible at f/4; in other words it represents the calculated "diffraction limited" performance at this aperture.
It is noteworthy that this test was conducted with a production lens on a production camera, indicating that the film was precisely positioned and flat.


PostPosted: Tue Sep 23, 2014 7:54 pm    Post subject: Reply with quote

poilu wrote:
The Zeiss Biogon resolve 400lp/mm, about 130 Mpixels
camera with more Mpixels than that are worthless because 400lp/mm is the limit of diffraction
even if the Biogon could have a resolution of 800lp/mm, physics wouldn't allow to record it


You need 2 pixels for each line-pair. So to fully exploit the resolution of that Biogon, a FF sensor should have about 550 Mpixels.