Since live and moving subjects are involved, I suppose there would be little contribution about using a fixed platform for automated bracketing like StackShot.
I choose to say focus bracketing here, since this is about taking pictures at different focus points.
Ok, here goes. Various methods I've done include ...
1) Using a Helicon Focus Fd ring. I don't suppose these handy items are still for sale since they were manufactured in Ukraine. I have used mine plenty times with my 100mm macro lens, as it uses electronic focus. I don't really consider this "manual" bracketing, but whatever works! Of course there are cameras these days that have built in focus bracketing and that would be a huge advantage, especially with mirrorless cameras that allow for blazing fast frame rates.
2) Very frequently I use fully manual bracketing by either turning the focus ring a little on the 100mm lens - with no Fd tube - or by nudging the camera forward a smidge each time. The super macro lens that I have (Venus/Laowa 2.5-5x) does not have a focus ring, so it seems I must always move the camera with that one.
> Moving the camera between frames likely introduces the most artifacts in a fully manual stack bc of small parallax shifts between foreground and background. It isn't that hard to move the camera in an instant to re-acquire the subject in the frame, and quickly brace the camera. But trying to then move the camera exactly down the axis of the lens for each picture -- that is tricky and I doubt I succeed entirely. I try to minimize parallax shifts by noting where the central reticule is on the subject, and making sure that it’s in the same spot each time. I can frequently get 3 or 4 usable frames in, and sometimes 10-12 if I am in a comfortable position and if the subject lets me.
> Bracing the camera. Lots of methods depending on what composition is wanted and working height above the table. For working several inches above the table, the camera is rested on my fist, a stack of books, or a handy box. Just resting the camera on the table would be done for pictures at ground level. In any case, it helps to have the camera rest on a couple slick magazines, as the smooth paper allows for fine movement with little resistance. My camera has an Arca Swiss type base plate, and I would like to try to use that one day by fastening down a long Arca Swiss mount to the table to see if I can nudge the camera along it between pictures.
> Pressing the shutter can result in a small camera movement. So I like to use a simple remote trigger plugged into the camera. This is gripped in my teeth, and I press the button by gently biting it. The button is covered in tape to keep it dry. This is weird, and I don't think I've ever divulged it to anyone, btw!
3) Lighting. Well, that is always an issue. I usually use a flash, brand new batteries, and a back-up set of batteries. I try to work at low power. An external battery pack for the flash would definitely come in handy since recharging times would become less of an issue. Having a flash plugged into AC would be a dream! I've also used continual lighting sources, but a flash puts out more light, and that lets me shave down the shutter speed and ISO.
4) From a set of manually focus bracketed pictures, then comes the stacking program. Sometimes, as the stacking program aligns each frame I see they are surprisingly steady even though my bracketing methods are pretty crude. But very often the alignment phase looks like the pictures were taken on a trampoline. Amazingly, they might still line up well enough to be usable.
So what are your thoughts and ideas?
However, I did know one person who believed that. Me! Practicing hand-held focus bracketing, and then stacking the results taught me otherwise. It was very surprising how sloppy frame alignment can be, yet still yield acceptable results.