improving quality of 40x image

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ap
Posts: 57
Joined: Thu Sep 19, 2019 6:33 pm

improving quality of 40x image

Post by ap »

hi everyone - i hope i can get some guidance on this. been playing around with diffusers etc and heavy post processing, but still not happy w/ image (maybe i should be?)
this is a closeup of a lizard's belly scales (courtesy of one of our cats) taken with 5r, nikon bd 40x elwd (with the light channel blocked), 3 flashes at low intensity (1/64), some circular rosco diffusers, and approx 2micron steps. post processing w/ light room and topaz detail. what do you all think i need to do to improve the image?
thank you so much for your input
andy
2022-02-24-01.18.19 ZS retouched-Edit.jpg

rjlittlefield
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Re: improving quality of 40x image

Post by rjlittlefield »

I have no idea what your lizard's belly scales are supposed to look like, so it's hard to know how well you've done at capturing them.

If you're new to high mag, then you're probably struggling with diffraction blur. I assume your nikon bd 40x elwd is NA 0.50. At rated magnification, that objective will be running at effective f/40 (=mag/(2*NA)), and that's deep into diffraction territory on most modern sensors. Assuming your camera is Canon R5, pixel size 4.39 microns, then that objective has a diffraction cutoff limit around 1 cycle every 5 pixels (for green light), and there's no significant contrast until quite a bit coarser than that.

So, you'll need to be doing very heavy post processing, with sharpening that is so strong it would convert an ordinary image to trash. Even so, you need to control your expectations because there's no way to sharpen your way past that diffraction cutoff of roughly one cycle every 5 pixels.

--Rik

ap
Posts: 57
Joined: Thu Sep 19, 2019 6:33 pm

Re: improving quality of 40x image

Post by ap »

thank you rik - as always your answers are very helpful. as i think many of us are, im quite conscious of overdoing the post-processing, but ill guess ill have to give it a try. I've used the same llens on butterfly wings and the results were a bit better - perhaps because the anatomy is somewhat more forgiving?
thx again, andy

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