Diffraction blur with the R5 and four prime lenses

Karl_Guttag wrote:

"Diffraction limit" is basically when you can't resolve two lines due to diffraction. Diffraction is an analog effect and not all or nothing. Whether your images are limited by diffraction depends on many factors, including pixel size. As pixels get smaller (and thus can resolve more lines per mm) diffraction has a more significant effect.

The bottom line is that a top-quality lens in the center with a high-resolution camera will start softening due to diffraction almost immediately.

From: https://teltec.de/out/media/canon-eos-r-white-paper.pdf

Thanks Karl -- I have attached a comparison I prepared of current and potential (shown in salmon pink) Camera Body Sensor Resolutions and Diffraction "limits". The term "limit" is not a hard stop, rather it is the aperture beyond which (ie more closed down) the impact of diffraction becomes increasingly visible reducing the effective resolution of images taken.

The Pixel Wars in 35mm, APS-C , Micro 4/3rd and SmartPhones are just "stupid".

I did a lot of looking and a little analysis of what I found. I can thoroughly recommend the following websites: Digital Picture , Cambridge in Colour, PhotoPills.com and by far the most detail and useful Scantips.com.

The 2nd argument against ever more MP and higher and higher resolution is all about the adverse impact of diffraction, which becomes increasingly visible with ever finer and finer the pixel pitch (and high and higher resolution per mm2) at lower and lower aperture values. The first is genuinely "who needs it" - sure fast card makers and computer and SSD manufacturers love it. Rather like 8.1k 12-bit RAW videos -- why?

The data is clear the effects of diffraction may start to be seen when shooting Sony AR7 IV with its 60.2 MP sensor at f/5.7 and will certainly be apparent when closed down to f/8.5 and beyond. A 90mp sensor on a A7R V or Z8 or R5? and whatever follows would be even more impacted - diffraction may be seen at f/4.4-4.5 and definately be visible at f/6.6-6.8 (the sensors are very different sizes).

AND the same is seen on the 32.3MP APSC cropped sensor Canon R7 (f/4.7 - f/7.3). This means that unless one is shooting close to wide open, with all that this means for the depth of focus, the resolution of the images taken with these "ultra" high resolution sensors (with increasingly tiny pixel pitch) will be diffraction limited. This is before considering the resolving capabilities of the lens.

Whereas the same calculation for a ~45mp R5 or Z9 are f/6.6 and f/9.8 and the ~24.3mp R3 or Z6II are f/9 and f/13.4. AND so on.

It is no surprise that higher resolution 35mm sized, Dx/APS-C sized and smaller sensors are adversely impacted by earlier at relatively wide apertures and this adversely impacts "resolution" more and more as apertures are closed down. While it is true that the early effects of diffraction (ie at the values I indicated above) are most probably only visible in bench tests using very fine targets and analytic tools -- gone are the days one uses a lens at f/16 or even f/32 on a high res sensor to shoot still life. Now we must routinely use automatic focus stacking at the optimal point for the lens/system one is using -- which is almost always wider open than the values shown above (in in my table).

AND where cameras offer HiRes mode (or pixel shift shooting) extraordinary resolutions and results can be easily achieved with a 35mm system. Of course should one transition to the GFX100 or IQ4 then extraordinary is not enough of a descriptor for what one can do at the highest end of shooting.

ULTIMATELY -- please don't just get sucked into the pixel wars -- buying ever more and more resolution -- you simply become prey for those that sell you fast and faster computers, larger and larger SSDs and yes better and better glass.

How about just buying what you need to do your job or want to enjoy. For some of us that is 45mp 20fps/30fps and even 11mp at 120fps (once or twice in 7 months) -- which is perfect and my camera used rarely at those settings. Most often I shoot single-shot or 3-5fps. For others (including most news and sports shooters) 19-24mp JPG is what they take, sell and squirt to their photo-desks within seconds and they do more than just fine. Most tourists can barely handle 5-11mp and this is already far more than they need. They certainly do not have the desire to buy or carry ultra-fast lenses with very high resolving capability and transmission losses. So what is to gain from putting a 18-300 travel lens on a 60mp sensor -- only the salesperson paid commision does well from that deal.