On 7/12/2015 12:10 PM, Mike Gordon via olympus wrote:
Been a bit under the weather of late so could not respond to posts I should
have, or at least felt compelled to respond.
Focused Moose writes:
<<<Moderate softness from diffraction that can be partially corrected with
deconvolution*
Yes, at first blush one would not predict either exact PSF deconvolution as
used by Canyon or blind R-L deconvolution as used in FM would work very well
due to the obliteration of some high freq detail at a hard cutoff from
diffraction which is distinctly different than Gaussian blur.
I did post something to that effect:
http://lists.tako.de/Olympus-OM/2013-02/msg01884.html
Why do you think I footnoted to you?
Empiric evidence mounting to the contrary , revisited that issue and also
spotted a review by Roger at Lensrentals.
http://lists.tako.de/html/Olympus-OM/2013-05/msg02068.html
http://www.lensrentals.com/blog/2013/03/overcoming-my-fentekaphobia
So the Diffraction monster's teeth aren't that long and non-determinate PSF
deconvolution can still improve the images.
To quote my own post:
As in the pin-hole
example, I neglected to consider that in diffraction softened images
deconvolution sharpening can (with non-determinate PSF's) do increase
detail CONTRAST, though you can't really increase the maximum detail
frequency.
OK to stop down a bit more than originally thought
The proof is still in the viewing of the pudding. :-)
As you quoted Roger before:
"The message I took away, though, is that diffraction softening is
real, it occurs where it is supposed to, but it’s really not as severe
as I had thought. Even on the D800 resolution is as high, or higher, at
f/16 than it was at f/2.8. At f/11 the resolution is as good, or
better, than at f/4. And at both f/11 and f/16 resolution is clearly
higher than it was wide open. Perhaps the diffraction monster’s teeth
AREN'T as long and wicked as I thought."
Not so Red in Tooth and Claw Moose
--
What if the Hokey Pokey *IS* what it's all about?
--
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