Stacking aberration tip please

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MBI
Posts: 2
Joined: Thu Sep 30, 2021 12:59 pm
Location: Paris

Stacking aberration tip please

Post by MBI »

Would be very grateful if an experimented member be kind enough to please help me find a useful resource to either prevent (or rectify) the area of the white background surrounding the nearest crystals from being stacked on top of the overlapped farthest crystals.
Capture001.JPG
Setup:
- MJKZZ Ultra rail mini V2
- D800
- Raynox DCR 150 reversed at 200mm from sensor
- Mitutoyo M Plan Apo 10x N/A 0.28
- Custom diffuser
- Godox flashlights
- 4µm steps for a 1548 µm course (that's 387 shots)
- Helicon with depth mapping (method B radius 8 smoothing 4)
- Photoshop CS5.1

May be my fault, but correcting in Helicon does a rather messy job. Have also tried methods A to C stacking with varying radiuses and smoothness without success. Unsure how Photoshop CS5.1 could help at all.

Very many thanks in advance for any kind help and any topic link as I didn't find that myself using the photomacrography.net forum research tool (apologies).

rjlittlefield
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Re: Stacking aberration tip please

Post by rjlittlefield »

There is no perfect solution to this problem. The difficulty is that the camera never saw exactly what you want to appear in the final output. For discussion of this point, see viewtopic.php?p=102557#102557 and follow-on postings in the same thread.

Your best bet is probably to combine the best parts of Method B and Method C, either using retouching inside Helicon Focus or using clone tool inside Photoshop.

--Rik

MBI
Posts: 2
Joined: Thu Sep 30, 2021 12:59 pm
Location: Paris

Re: Stacking aberration tip please

Post by MBI »

Many thanks for the thread suggestion. Will look into it asap.

Also came across to what is known as slabbing (https://enrico-bonino.eu/sub-stacking-in-helicon-focus/). Have tried it, but much messy Helicon retouching still needed.

Tested the same subject on a black background, which stacks with very little overlapping issues in one go (no slabbing). Are stacking softwares low key oriented?

rjlittlefield
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Joined: Tue Aug 01, 2006 8:34 am
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Re: Stacking aberration tip please

Post by rjlittlefield »

The issue is probably a matter of how much light is coming from things that you care about seeing, versus things that you do not care about like unfocused background.

When there is too much light from things that you do not care about, gradients in that unfocused bright light are likely to be stronger than real detail in the darker regions that you care about. When this happens the software is liable to show you the unfocused light instead of what you want.

I'm not sure whether it is best to think of this as an issue with stacking softwares, or as a general signal-to-noise issue that appears in stacking. But in any case, yes, it is best if most of the light comes from things you care about.

--Rik

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