Pixel Peeping in 2020
What to do with the extra megapixels?
First came the 4-6 megapixel cameras and everyone was happy that they had instant pictures without waiting for the 1 hour drug store negative development (The D-lux was created in 2003 with 3.6 effective megapixels). Then came the 9-12 megapixel cameras and pixel peeping was born. With the increased picture quality everyone wanted to know just how much detail they could capture (The D-lux 3 had 10.2 megapixels, the M8 had 10.3 megapixels). Finally, the 18-24 megapixel cameras arrived and everyone again wanted to know how much more detail their lens would capture in an image (Think M9, M240, M10).
Today, with 40 megapixels in the new M10 Monochrom, 47 megapixels in the SL2 and 64 megapixels in the upcoming S3, pixel peeping has changed to resolution limits. We have started to realize that we can capture more detail than we need. Discussions on various forums are beginning to surround two concepts: image noise, and lens resolution. I see questions about the image noise resulting from using 25,000 or 50,000 ISO. I also see questions about whether the image will be “sharp” enough from a classic lens.
M10M-Elmarit90-ISO160-2
M10M-Elmar50Collapsable-ISO160-1.15sec-Handheld-3
These are both interesting questions to consider, because the answers require looking at the pixel level, which is irrelevant for most images from these new cameras. Leica has adjusted the pixel pitch very slightly over the years. The pixel pitch, or distance between the center of two adjacent pixels, is 6.9 microns for the M8 and M9. The M240 and M10 both have 6 micron pixel pitches. However, the new generation of sensors from Leica are now using 4 micron pixel pitches, which translates to almost a 50% reduction in area per pixel.
Noise Noise is part of every digital image. However, noise is created at the pixel level. Pixel size determines the size of the noise in the final output - digital and print - and smaller pixels are less visible given the same size output. Understand that noise is still present and except for technology advances, noise is essentially the same regardless of pixel size. The next question might be, if an image created with smaller sized pixels appears to have less noise, why not make 35m sensors with 100 megapixels? The answer lies in dynamic range.
M10M-Noctilux10v1-ISO12500-1
M10M-Noctilux10v1-ISO3200-1
Think about the grain size in black and white film. Grain of the Ilford FP4+ film shot at ISO 125 is not easy to see compared to Ilford 3200. Larger grain is more sensitive to light (ISO 3200) and smaller grain needs more light (ISO 125). In addition, negatives from the Ilford FP4+ have a wide range of tones and the Ilford 3200 has very high contrast with much fewer tones. The same is true for sensors, noise is still there, but it is represented in much smaller sized dots, much like silver halide grain. Yet, it takes advances in technology to maintain the same dynamic range between sensor sizes.
M10M-Noctilux10v1-ISO50000-3
M10M-Noctiulx10v1-ISO50000-1
Thus, at equivalent ISO’s, it appears like the noise is much lower at the same viewing size. Said another way, it may take twice as much noise to be visible in ways we are used to viewing images, so we can use higher ISO’s. Some of the images here were taken at ISO 50,000 and I considered very usable for enlargement with smooth tones throughout.
Side Note: At ISO 50,000 I recommend exposing for the mid- tones, letting some of the highlights blow in unimportant areas. The images come out with significant tonality and there is much less noise in fine details for enlarging the image later. The images at ISO 50,000 here were exposed in that manner.
Not accounted for yet are the advances in CMOS sensors which reduce the electronic noise compared to earlier sensors. An article published May 3, 2015 by Richard Butler at Digital Photography Review discusses sensor noise at a very deep level using some sophisticated math. Butler discusses read noise of different sized sensors, which is the noise generated by reading the data from the sensor. His conclusions show that most camera companies will not use sensors with higher pixel counts until they can control the read noise, which can produce a system with overall lower noise and hence, higher ISO’s. This seems to be exactly what Leica have done moving from 24 megapixels to the over 40 megapixel range and adding one to two stops of additional ISO capabilities.
M10M-Noctiulx10v1-ISO50000-4
M10M-Noctiulx10v1-ISO50000-2
Resolution In terms of lens resolution, I have continued to indicate the M10 Monochrom produces film-like results on the classical M lenses, or lenses that do not contain aspherical elements. I call these lenses “classical” but there are others. In fact, the images included here are all labeled with the lens used and all were taken with the M10 Monochrom. The lenses used were a) version 1 of the Noctilux-M f/1.0 50mm, b) the German made Summilux-M f/1.4 75mm (as opposed to the Canadian version) and c) the chrome Elmarit-M f/2.8 90mm
– all non-aspherical lenses designed by Walter Mandler. One image was taken with the newer version of the Elmar-M f/2.8 50mm Collapsible (chrome) lens with only 4 elements, none aspherical.
I have found images shot at low ISO’s on the M10 Monchrom show much more shadow tonality than previous Monochrom models (Type 246 and CCD). The increased pixel count allows standard viewing sizes to show the appearance of much smoother graduations between tones even with some of the more classical lenses. The high resolution approaches the visible contrast levels of these older style lenses wide open. In different terms, as the limits of lines drawn by the older lenses approaches the size of lines drawn with the pixels, the maximum image recording has been reached.
I would argue that, stopped down, the classical lenses frequently have higher resolution capacity and clearly the newest APO ASPH lenses have even higher resolution, like the LHSA special edition APO Summicron 50. However, the classical lenses still have a place in producing quality images with these new high resolution sensors. I would also note, however, that in order to produce medium format prints, the classical lenses would typically require some cropping to remove aberrations at the image edge. The more modern APO lenses win here as well and typically produce fine details throughout the image and to the very edges.
M10M-Summilux75-F1.4-1.90sec-ISO6400-Handheld-1
M10M-Summilux75-F1.4-1.60sec-ISO6400-Handheld-2
As a comparison, think about images produced by 1949 Summicron Collapsable screw mount lenses from a 24 megapixel sensor on an M9 or M240. Wide open, even on film, the lens produces soft images. The contrast capability of these lenses is less than the sensor resolution making the image appear soft. We have clearly reached another plateau with the new 40+ megapixel sensors on non-ASPH lenses wide-open. At the same time, Leica have told us that the newest APO M lenses have yet higher resolution limits, so there may be room to grow!
What to do with the extra pixels? The question remains, what to do with the extra pixel resolution in these digital files? Some have suggested they can crop plenty and still end up with a 24 megapixel image. They may use a 35mm lens and crop to a 50mm lens (think Leica Q2). I create 13 x 19 prints from 24 megapixels with great success. Personally, I like the ability to shoot on a tripod and create images that I can print at 17 x 22 inches in native resolution with a small sized camera body. Also, the increased dynamic ranges of the new generation of sensors starts to compete with dynamic ranges of my black and white films and the S3 should provide a whole new level of color creativity. I have never worried about grain in black and white film - my two favorites being Ilford FP4+ and Kodak Tri-X 400 and I loved the boost in dynamic range and detail from the M9M and the M246 compared to the color brethren. Now the M10 Monochrom is my favored grab because the upgraded CMOS and resolution effectively eliminate the noise for most applications and provide incredible tonal ranges, especially in the shadows.
Yet, all this talk about noise and resolution takes away from the primary purpose, which is to create images. Each of these new high resolution cameras has a place in taking photographs. Clearly given the choice, pressing the shutter is better than thinking about whether the image will be sharp enough and missing the shot. Interestingly, this discussion about whether the tool is sufficient technologically speaking, versus using the tool to create images has been around for over half a century.
A 1954 Perspective I recently ran across a unique piece of history. I enjoy history and the uncovering of some important wisdom or new concept that remains relevant today always piques my interest. The June/July 1954 issue of LFI Fotographie contains one such relevant reminder on page 121 and its relevance here is startling.
Titled “The Exaggeration of Technique,” the editor points out to the readers the reliance on technique. To put the article in perspective, the Leica IIIF screw mount body was the forefront of technology. Made from the 1950 to 1957, the IIIF was the second to last design before the M series. Thank you to Bernd Luxa of LFI Photographie GmbH for granting me permission to share what the editor says in this article and for providing an image of the original article.
Miniaturists so often develop a complex about the sharpness of their pictures. The print is carefully examined all over with a magnifying glass because it appears that there is no better criterion for the quality of a picture than the proud declaration: ‘You can’t distinguish it from a plate negative!’
Today, such achievements are little cause for congratulation because we now have lenses and single-coated films of the highest resolving power. One seems to forget that technical quality is a necessary adjunct of every picture, but certainly not the be all and end all of the good photograph. Technical excellence is indispensable in many fields - architecture, aerial, commercial and copying, to name a few - but there are also other tasks where lack of the ultimate in technical quality does not detract one jot from the worth a picture: reportage, press photography, documentaries.
Think of the pictures of a Cartier-Bresson, of war photos from Korea or Indo-China, and one must admit that such pictures are looked at much longer than many others in order to re-live a situation. And why? Because their message is urgent, incisive. Who would quibble about technical quality when emotional content is high? Is not the latter much more significant?
It is unwise to build things up into a fetish. Technical quality is a good thing in the right place and wherever its presence is a sine qua non. It is well to be armed with the ability to produce it because it is a thing that is accepted as read. But it is equally important, often more so, to give credit to momentous pictures produced under circumstances which often preclude the possibility of a technical tour de force. More important than all technique are content, impact and the imaginative force that compel the attention of the observer. This is a plea — not a plenary indulgence for the inept!
How interesting that the same concept applies today. With the flat digital sensor and current digitally refined lenses, the pixel peeping reports of slight aberrations in the extreme edges of the image remain relevant in new camera evaluations. With the ease of stumbling on such information, I too fall prey. A more important aspect of photog- raphy would be long studies of iconic or important images made by very successful photographers - understanding the why behind the image. With these new sensor sizes, perhaps we can forgo the pixel peeping and make more images. The quality of the digital images is clearly present in these new sensors.
The next time you see an image that captures your attention, study the photographer’s message and try to discern how and why they took the image from the specific angle and with specific content or context. The next time you look at a camera review, try not to worry about the pixel level detail, but think about the possibilities and the images you can produce with the camera - even if you have to crop the image. And by all means, think about what you will do with all these extra pixels!