Steve Spencer wrote: Jack Flesher wrote: Steve Spencer wrote:
The key point is that for most lenses the system MTF changes significantly with different sensors, but at higher resolutions a diminishing return is seen and you need really good lenses (often stopped down) to benefit from the higher resolution.
I think you meant “NOT stopped down beyond diffraction aperture” …
Steve Spencer wrote:
Those diminishing returns may very well be why camera companies aren't making the higher resolution sensors they could make.
That was exactly my point. 👍
Obviously if you stop the lens down too far and diffraction kicks in strongly that would be a problem, but many of the best lenses still benefit from stopping down a little. So, in Brandon's analysis he was using the DSLR Zeiss Otus 85 f/1.4 and that lens will be better stopped down to f/2.8 than it is at f/1.4 and we aren't talking about any issues with diffraction at that point and even just past when diffraction starts to affect the image, the improvement might be on some lens greater than the impact of diffraction. I have always found the term diffraction aperture or especially diffraction limit misleading. The effects of diffraction are gradual as you stop down and exactly when stopping down benefits vs hurts performance has to be tested with each lens and not attempted to be quantified by something like a diffraction aperture.
Exactly, because f2.8 is before the diffraction aperture for the 60mp sensor and f4 is already beyond the beginning of diffraction.
Steve Spencer wrote: Jack Flesher wrote: Steve Spencer wrote:
The key point is that for most lenses the system MTF changes significantly with different sensors, but at higher resolutions a diminishing return is seen and you need really good lenses (often stopped down) to benefit from the higher resolution.
I think you meant “NOT stopped down beyond diffraction aperture” …
Steve Spencer wrote:
Those diminishing returns may very well be why camera companies aren't making the higher resolution sensors they could make.
That was exactly my point. 👍
Obviously if you stop the lens down too far and diffraction kicks in strongly that would be a problem, but many of the best lenses still benefit from stopping down a little. So, in Brandon's analysis he was using the DSLR Zeiss Otus 85 f/1.4 and that lens will be better stopped down to f/2.8 than it is at f/1.4 and we aren't talking about any issues with diffraction at that point and even just past when diffraction starts to affect the image, the improvement might be on some lens greater than the impact of diffraction. I have always found the term diffraction aperture or especially diffraction limit misleading. The effects of diffraction are gradual as you stop down and exactly when stopping down benefits vs hurts performance has to be tested with each lens and not attempted to be quantified by something like a diffraction aperture.
Exactly, because f2.8 is before the diffraction aperture for the 60mp sensor and f4 is already beyond diffraction.
Jul 03, 2026 at 01:19 PM
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