It is a very murky area. OM System uses “differential” units on a scale of 1 to 10 and my Fuji uses “steps”. But neither of those are much help.
It would be nice to have a reliable way of working out the approximate distance these steps relate to at a given focal length and aperture, without having to resort to some complicated cheat sheet drawn up from hours of trial and error.
Even for non-macro work, it should be possible to work out how many steps you need for something like a landscape where you want the foreground and infinity to be sharp. At least Fuji has a mode where you can actually set your focus point to the nearest and furthest areas of your scene that you want in focus, and it will calculate the focus bracketing steps based on how many shots you want. But OM System doesn’t have this, so you need to work it out from experimentation or just set a high number of frames and wait for the camera to automatically stop when it reaches infinity.
I wanted to better understand how the focus bracketing system works on my Canon R7 and I came across some interesting investigations by Jim Kasson. He suspects that the single step increments are determined by the f-number to maintain a given Circle of Confusion on the sensor and he has a series of test results that seem to confirm that. He has a procedure for figuring out the largest step size you can get away with on your camera, your lenses, and your subject matter, but if you do it once then the results should be broadly applicable across subject distances.
I ran some tests of my own and might share them if I can get the time. Here are the links:
I recently bought an AstrHori 85mm F2.8 tilt macro lens for my Canon R7. Having now tried tilt macro lenses I could not go back to a normal macro lens. Canon make tilt macro lens as well, but a bit beyond my preferred budget at the moment.
Nothing just yet. I have only just finished editing my photos from my African camping safari from August last year. I haven’t done much picture taking this year yet. I will use it for teaching students macro photography though. The tilt function is truly brilliant as DoF is so challenging with macros at the best of times.