I was using Zerene Stacker jargon. In dedicated stacking programs (Zerene and Helicon) there are different stacking algorithms. One is good at recording color tones and generates less noise, but it gives the worst in artifacts like halo effects. The other is the opposite for both. They are called DMap and PMax for Zerene. I think Helicon has 3 algorithms, with one being sort of in between the other two (?). Anyway, a common thing is to build the stack in the different algorithms, then use the low noise one as a starting point. Bits of the high noise picture are painted into the low noise picture in places needed to resolve halo and transparency artifacts. Original pictures used to make the stacks can also be painted in here and there to resolve problems that the hi noise stack can't fix, but that can be quite a chore if there are a lot of pictures, so each thing to fix needs several pictures.

I know next to nothing about the Helicon Focus stacking program, but Zerene Stacker is at least as good, and the online tutorials they provide are a thing of beauty and clarity to watch. I sort of know the person who made those tutorials, and he is just amazingly clear in how he explains things.

I will be way behind the curve where you and Sippy are concerned since I am more into informal stacking that can be done on a bouncy wood floor at our dining room table, with somebody walking by pretty frequently. Sippy would cringe at my environment! 🙂

Wow, thanks for looking Mark. You are way farther in to this than I am. Some of what you wrote I did not understand. Though you seem to have skipped through some of the points I did state. I used the software stacking program that comes standard with the WeMacro Rail. I only mentioned that I looked at some theoretical data and tables of information from the Zerene Stacker Web Site. I actually just stacked my images with Photoshop CS6. Yes, I am still using a purchased DVD-ROM version of Ps, the very last iteration from 2012. Now your comment about ISO I will heed. I had been shooting my Pentax cameras at their factory default of ISO 200. I found for at least this first stack I did the shutter speed was probably fine at 1/20 second. So I can probably take the camera down to ISO 100. It is all good and I'll comment more later and read more suggestions before trying another shoot.

Oh, what I did not understand was "Try both DMap and PMax." I guess these are Zerene things; different algorithms? I did notice the halo and a few remnants. This being more a test of the rail and stacking, I did not want to spend too much time editing or cleaning it up with Photoshop. Though it might be a good one to try as a learning practice. Thanks again.