LEICA Barnack Berek Blog: THE PIXEL RACE IS ON AGAIN

Saturday, August 3, 2019

THE PIXEL RACE IS ON AGAIN

A few years ago camera manufacturers created the impression that a higher resolution (more pixels) sensors would automatically result in better photographs. That, however, ignored other important aspects of a high quality digital file, like noise, ISO range, dynamic range, exposure latitude, color accuracy and more.

It became obvious that a higher pixel count would inevitably need to be paid for with a whole lot of shortcomings and the pixel race definitely slowed down. Most manufacturers settled on a full frame resolution of about 25 megapixels.

But lately a higher pixel count again garners interest. Some newly introduced full frame digital cameras herald resolution of 50 and even 60 megapixels and just this morning there are reports that Canon might introduce a full frame camera with a sensor of 80 megapixels.

Obviously it cannot be argued that a higher resolution sensor will result in sharper images, as long as there are no other, image degrading side effects and as long as the lens on the camera is capable of dealing with that high a resolution. With other words, if a lens is only sharp enough to adequately deal with 25 megapixels, then all else is a waste.

But what is possibly gained by a higher resolution sensor? The main advantage lies in the fact that it allows for bigger enlargements or more severe cropping, both without loss of detail in the resulting image.

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Leica M8 (10.3 megapixel), 28mm f/2.8 Elmarit

Special applications not withstanding, how big an enlargement or how much cropping capabilities do we really need? This is a question everyone has to answer for him/herself.

So what are different camera sensors actually have to offer in this respect? Just some simple math offers considerable insight here.

It is generally accepted that with perfect vision, the human eye can resolve 10 lpm (lines per millimeter). However, that is under ideal conditions and a figure of 7 lpm is the generally accepted more realistic figure.

The sensor in the Leica M10 has a resolution of 5952 x 3992 pixels while new Leica Q2 resolution is 8369 x 5584. That means, without any other resolution deteriorating factors, the M10 can render enlargements of 80 x 57 cm (31.5 x 22.5 inch) based in the more realistic resolution of 7 lpm for the human eye. With the Q2 that increases to 119 x 81 cm (47 x 32 inch). Those are impressive figures and they bring up the question of how much more do we need.

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Leica M8, 28mm f/2.8 Elmarit

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Even a relatively low resolution of 5 megapixel can render quite acceptable results

Leica Digilux 2

The biggest enlargement I have hanging in my house is 28 x 22 inch. That is quite an exception. The limiting factor for me is available wall space. After all, why make an enlargement if it is not displayed? The capabilities of the Leica M10 would have been capable of making that enlargement, as a matter of fact; another aspect of this discussion must be viewing distance.

Even the more realistic figure of 7 lpm is based on a viewing distance of approximately 12 inches. While that is realistic for small prints, like the common 8 x10 inch enlargement, that is unrealistic for much larger prints. There we usually view a picture from a greater distance which further reduces the resolution requirements. With other words, an even bigger enlargement would look perfectly sharp, even is the resolution was less than 7 lpm.

Of course cropping requires greater care if the resulting enlargements are of a more reasonable size. These are viewed at a closer viewing distance and thus would reveal any shortcomings in resolution a lot sooner.

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Leica M240, 28mm f/2.8 Elmarit

I rarely use image files straight from the camera. I have found that most images can be considerably improved by post processing. Subsequently another limiting factor might be the capabilities of our computer systems. If it becomes difficult for a computer to handle the much larger files of a higher resolution camera, and if the higher resolution is rarely, if ever fully taken advantage of, it becomes further questionable if it is worth to consider such a camera.

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Leica M240, 28mm f/2.8 Elmarit

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Leica M240, 50mm f/2 Summicron

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Leica M240, 28mm f/2 Elmarit

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Leica M240, 50mm f/2 Summicron

Of course, other individuals’ mileage might vary in this respect, but for me, the 24 megapixel resolution of my camera has served me quite well and I see little reason to change. On the other hand, the Q2 has some advantages in terms of cropping. Being that the camera has a fixed lens, cropping to the field of view of longer lenses can be done to quite an extend without sacrificing overall quality of the results.

So it appears that the higher resolution figures that once again are creeping up in this discussion are primarily used as a carrot on a stick to lead potential camera buyers to invest in something that, in most cases, is unnecessary.