Artifacts (light or something alse)?

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All Ex
Posts: 261
Joined: Mon Jul 20, 2015 3:54 am
Location: Greece Thessaloniki

Artifacts (light or something alse)?

Post by All Ex »

Can anybody tell what is that artifacts round a dead ant I've found, over it? :

Image

The stack was made from raw files, which I`ve converted to tiff ones with Photoshop (68 ones, that made 14 slabs in Bugslabber). The rest of my setup is a D800, Mitu 5X in 4.5 mag with a Rodenstock-Gerogon at 150mm, in f9 that is in its wide open aperture, as a tube. In 1/200 shutter speed and all the flashes in 1/128 power.

This is my setup :

Image

I assume the light is too close, thus by taking the flashes more away from my specimen will do the job the proper way.
All--Ex
My YouTube initial video

rjlittlefield
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Re: Artifacts (light or something alse)?

Post by rjlittlefield »

All Ex wrote:Can anybody tell what is that artifacts round a dead ant
I assume that you're talking about various sorts of halos. Those look like typical artifacts that result when the depth map does not properly track the focused areas. This composition is particularly troublesome for depth map methods because there is 1) focused background far behind the subject in some places, and also 2) completely OOF background around the subject in other places. In area 2 you want the depth map to snap crisply from subject to background, but in area 1 you want the depth map to stay at the same depth as the subject. Using Zerene Stacker, moving the DMap contrast threshold slider to the right can eliminate the halos from cause 1, but that may make the halos from cause 2 worse. To get a completely clean rendering, you might need to render twice with different slider positions, then combine the results with retouching. Retouching from a PMax output may also help, especially in area 2. See the Advanced Retouching tutorial for discussion of these techniques.

Regarding the lighting, your color balance is very far off and you have (again) a large amount of veiling glare. I do not see evidence of general over-exposure, so moving your flashes farther back will not solve your problems until you have some light leak that is currently being directly exposed to the flashes.

--Rik

All Ex
Posts: 261
Joined: Mon Jul 20, 2015 3:54 am
Location: Greece Thessaloniki

Post by All Ex »

I`ll have to apply very carefully those things this advanced tutorial says, I`m aware that my WB is bad, you can see the yellow in the second image that is the actual background of the image.In a third, irrelevant, time I`ve played with it forgetting afterward to adjust it.
Thank you for your lights, Rik.
:smt023
All--Ex
My YouTube initial video

All Ex
Posts: 261
Joined: Mon Jul 20, 2015 3:54 am
Location: Greece Thessaloniki

Post by All Ex »

After applying Rik`s suggestion:

Image

The problem is sold in tiffs that I'm working, unfortunately, the site does not support that kind of files. In png form kept telling me that the file exceeds the size, it is capable to manage, thus I posted that small image.
You can see though that the shadows disappeared.
Rik wrote:This composition is particularly troublesome for depth map methods because there is 1) focused background far behind the subject in some places, and also 2) completely OOF background around the subject in other places. In area 2 you want the depth map to snap crisply from subject to background, but in area 1 you want the depth map to stay at the same depth as the subject. Using Zerene Stacker, moving the DMap contrast threshold slider to the right can eliminate the halos from cause 1, but that may make the halos from cause 2 worse. To get a completely clean rendering, you might need to render twice with different slider positions, then combine the results with retouching
To avoid all that procedure would it be helpful if I placed my colored background ( which is in 45 degrees angle ) far behind?
When using bugslabber you don't have the option to adjust the threshold slider as you pleased.
Finally, it was proven that the cause of the artifacts was the DMap method I used processing the slabs that I made with PMax (the false adjusting of the parameters of it).
:?:
All--Ex
My YouTube initial video

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