As background information... I'm the fellow who wrote Zerene Stacker. I also answer all the emails that come in to
support@zerenesystems.com, which means I've looked at quite a few problems.
In general, Photoshop makes what I call "errors of
omission", leaving blurred areas that were sharp in some source images. If you could have completed this stack using Photoshop, I expect you would have had pretty large loss-of-detail halos around each of those foreground elements, where they overlap focused background. In contrast, Zerene Stacker and Helicon Focus are better at retaining focused detail, but are more prone to "errors of
commission" by introducing artifacts like transparent foreground and halos of various sorts.
People who are new to stacking often prefer Photoshop because its errors are harder to see, especially when you're still getting used to seeing so much other stuff in focus. But with more experience, those loss-of-detail regions become more annoying, and then you run up against the problem that Photoshop has essentially no controls over its operation. Sometimes it produces a good result, and then everybody is happy. But often it does not, and then there's nowhere to go except manual retouching, defect by defect from source. In contrast, Zerene Stacker and Helicon Focus provide more variety of controls and methods that can produce a better automated result plus simpler retouching. The tradeoff is that the extra power comes at the cost of having a longer learning curve.
With Zerene Stacker, the best results for stacks like you're showing here are often produced by using a combination of DMap and PMax stacking methods, followed by manual combining of the best parts of the DMap and PMax outputs by using the retouching tools. DMap should be able to give a clean result for almost all areas of this subject, leaving only the edges of foreground/background overlaps to be cleaned up from PMax. There will likely be some areas like the big bristles that show transparent foreground. Those could be fixed by retouching from source, or if you're farther along the learning curve, by using Stack Selected to make a single clean intermediate image of just the bristle, to use as a source for retouching. The methods to do this are discussed in the tutorials linked at
https://www.zerenesystems.com/cms/stack ... rialsindex, most notably "How To Use DMap", "Introduction to Retouching", and "Using Stack Selected To Retouch Transparent Foreground".
When using DMap, take care to avoid the common error of moving the contrast threshold slider too far left, so that the entire frame appears in natural colors. This will cause a very bad appearance of the background. Instead, slide the slider to the right until the entire OOF background gets masked as "black in preview". Some portions of the subject having no strong detail will go black at the same time; that's OK. Seeing only your result, and not the full stack, I'm thinking that a slider value in the vicinity of 55-60% will be about right. (The percentage is fraction of the frame area covered by mask. The best value varies widely with composition.)
In the most recent version of Zerene Stacker, there is also a control to change the mask color. In stacks like this one, where the background is itself black, the masked area is much simpler to see if the mask is made some other color, such as partially transparent dark red like Photoshop's "rubylith" masks. See
http://www.photomacrography.net/forum/v ... 728#211728 for an illustration of that technique. With a rubylith mask, here's a quick summary of how I'd suggest to set the slider:
I hope this helps!
--Rik
