Diffraction Limit Discussion Continuation

Started 8 months ago | Discussions thread
tt321
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Re: Duck, duck, goose.
In reply to Jonny Boyd, 8 months ago

Jonny Boyd wrote:

tt321 wrote:

Jonny Boyd wrote:

Close.

'The diffraction limit for a system occurs at the aperture at which any further reduction in settable aperture size will cause a visible decrease in image resolution.'

'for a system' clarifies that the sensor resolution and viewing method are factors.

'settable aperture size' allows for the fact that different lenses have different limitations on how precisely the aperture is controlled.

You do realize that for practical purpose, this definition of 'diffraction limit' has zero meaning for cross-system comparisons, esp. regarding systems with the same sensor size but different sensor pixel counts (i.e. different physical pixel sizes)?

Who ever mentioned cross-system comparisons? Though the work I've done looks at sensor resolution without specifying sensor size.

Answer both your questions below.

And more specifically, the particular interpretation that sensors with higher pixel counts are somehow worse than those with lower pixel counts because one could notice the 'visible diffraction limit' earlier is pure nonsense.

I'm baffled as to why you would need to say that when it has repeatedly been affirmed over and over and over again. I mean really, where did anyone ever suggest that a higher pixel count would produce a worse image? I'm sick of that being thrown out as if anyone had made the claim.

Even within this very thread, we have this:

http://www.dpreview.com/forums/post/53168527

The way this thing has been presented has caused a lot of confusion. In other words, people hold cross-system comparisons and within-format comparisons based on using this thing you defined as 'visible diffraction limit' as a criterion.

You repeatedly stated that you are not in the least interested in digging out who done what but you seem to be implying that my message was to do with that. I assure you it's not. Specifically I did not say, and am not interested in saying, that you hold any of those views. I am trying to say that I can see no practical use for the concept of 'visible diffraction limit', if we leave out cross-system or cross-sensor pixel count comparisons.

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