Why is photo sharpening necessary

Here you can discuss topics such as focus stacking, stitching and other techniques that relate to the processing of micrographs.
Post Reply
Message
Author
sreynolds
Posts: 107
Joined: Sat Oct 10, 2020 1:17 am
Location: Vermont, USA

Why is photo sharpening necessary

#1 Post by sreynolds » Wed Nov 01, 2023 12:29 am

Almost all my images benefit from sharpening - I'm using GIMP photo editor. The two images below are a rather extreme example, but the blurry image is much improved by sharpening, without any apparent (to me) degradation. Subject in Hydropsychidae larva. The details derived by the sharpening process must be present in the original image. Is there some adjustment to be made in the camera configuration that would accomplish the sharpening up-front? Is there a reason this is not desirable? Would more or fewer pixels help? Maybe higher ISO speed? I have 2 mirrorless cameras - Olympus Pen-E PL7 and Canon M200, and they both behave similarly in this regard. Thanks.
PA040009_1.JPG
PA040009_1.JPG (111.39 KiB) Viewed 3289 times
original
PA040009a_1.JPG
PA040009a_1.JPG (189.33 KiB) Viewed 3289 times
sharpened
Steve

Scarodactyl
Posts: 2746
Joined: Sat Mar 03, 2018 9:09 pm

Re: Why is photo sharpening necessary

#2 Post by Scarodactyl » Wed Nov 01, 2023 1:08 am

In extreme macro and micro we are always near to the diffraction limit relatively speaking, not much we can do about that (nothing at all past a point). But we know diffraction blurs things, so by subtracting a blurred version of your image from the image you can partially reverse it. It seems dumb but it works (blind deconvolution).

J_WISC
Posts: 107
Joined: Sun Mar 06, 2022 7:28 pm
Location: Wisconsin, USA

Re: Why is photo sharpening necessary

#3 Post by J_WISC » Mon Feb 05, 2024 2:21 pm

Scarodactyl wrote:
Wed Nov 01, 2023 1:08 am
blind deconvolution

Thank you for providing the term for this.

Now I’m wondering whether better stacking software has settings for this.

https://en.wikipedia.org/wiki/Blind_deconvolution

Topcode
Posts: 52
Joined: Sun Nov 05, 2023 8:29 pm

Re: Why is photo sharpening necessary

#4 Post by Topcode » Mon Feb 05, 2024 7:44 pm

J_WISC wrote:
Mon Feb 05, 2024 2:21 pm
Scarodactyl wrote:
Wed Nov 01, 2023 1:08 am
blind deconvolution

Thank you for providing the term for this.

Now I’m wondering whether better stacking software has settings for this.

https://en.wikipedia.org/wiki/Blind_deconvolution
May i recommend the use of registax? Its intended mainly for planetary astrophotography, but ive used it for correcting CA, color correction, and some sharpening, on my microphotography.

Post Reply