06-19-2016, 10:06 PM
Quote:Totally agree on what you say above. However, I still don't understand what you mean by this statement:
F9 and F11 are well into diffraction territory with current (16 and 20MP) MFT sensors.
The problem really is the word diffraction territory - there si no such thing.
A sensor is "diffraction limited" (essentially the wrong word, which is why I put it in quote marks), when the aperure used produces a resolution which by definition is less than the resolution of the sensor. Diffraction limits for a sensor in principle occur at teh Nyquist frequency, and if you compare diffraction limits for different apertures, you'll find that when using teh Rayleigh criterion, this limit occurs at around F/12 and F/11, and ideally, because of other factors, one should use a stop larger to get optimal results, i.e., F/9 and F/8 (made a typo in my earlier post; I'll correct it), or, even larger apertures, obviously.
And what do you mean that it is more visible the the higher the sensor density is?
You will see sharper jumps in resolution going from aperture to aperture with higher density sensors, than you do with lower density ones, but thatis not so much related to diffraction as to sensor resolution itself.
If you click on the pictures I attached, you will see that the differences between resolution figures at larger apertures between the different sensors is greater than at smaller ones. This means that the drop off in system resolution is steeper once you go beyond teh apertures where a lens is best. That is all there is to it.
When I get a chance, I'll draw some resolution graphs to show what I mean.
HTH, kind regards, Wim
Gear: Canon EOS R with 3 primes and 2 zooms, 4 EF-R adapters, Canon EOS 5 (analog), 9 Canon EF primes, a lone Canon EF zoom, 2 extenders, 2 converters, tubes; Olympus OM-D 1 Mk II & Pen F with 12 primes, 6 zooms, and 3 Metabones EF-MFT adapters ....