Peterfiore presumably has it.
>But cameras that do focus bracketing generally use "steps" of focus bracketing, which is an number that is proportional to how much the focus changes for each picture. A small number means tiny focus changes, so lots of pictures are taken to focus thru a scene. This is done at wider apertures, so very shallow depth of field and appropriate for macro work where the scene is millimeters deep. A larger number means larger focus steps. This is appropriate for wider apertures, so greater depth of field and is appropriate for close up photography where you don't want to take a zillion pictures to get thru a scene that is several inches deep.
>You can continue taking pictures out to infinity if your lens permits it (not all macro lenses do).
>Of course the big question is 'what do those step numbers mean in terms of
amount of focus change? Is it 1/2 millimeter per picture? 5 millimeters? How many pictures do I need to take to focus bracket thru a given scene? And the answer is
it depends on the lens, and
it depends on the scale of the scene. You just have to accept that you won't really know until you calibrate things.
I have a similar set-up, where I can focus bracket thru a macro or close-up scene, and I use 'steps'. What I had to do was calibrate my system so I'd know later what to do for a given situation. This involved setting up the camera on a tripod in a controlled setting, without vibrations, and then focusing on something up close that had lots of detail and it was viewed at a steep angle so that only a narrow part was in focus and the rest quickly faded into non-focus. I think I used a dollar bill. I set the camera to a wider aperture that gave maximum sharpness for my lens (f/6), but this is very shallow depth of focus for that lens. I tried different step sizes. Very small step sizes were too small, where the focused areas in each picture extensively overlapped each other. It would require lots of unnecessary pictures to get thru a scene.
Considerably larger step sizes (something like 50x larger step sizes) were too large. There were unfocused areas between each picture.
>One of our major contributors has a post that clearly illustrates this very issue:
https://www.uglyhedgehog.com/t-456907-1.html >By experiment, I found an optimal step size for that lens and aperture where the focused areas overlapped but only a little. I could focus bracket thru a scene with a minimal # of pictures. When I found that, I wrote it down, and I keep it where I can always find it. What that step size is does not matter for you, since your values can easily be different.
> I repeated this for wider apertures, since I do want to also do close up focus bracketing of larger subjects. This soon took less time b/c I quickly caught on to how much I'd need to change the step size for successive apertures.
> Your camera also has the Frames setting. This is where you tell it how many pictures to take. I'm not sure what to say about that except that if the number of frames falls short of what you need, you probably could simply do another run from where you left off. If 50 frames wasn't enough. Do another 50.
> A common follow-up question is where one asks: How many pictures will I need to take to focus bracket thru this scene? The answer is:
You don't need to know. Just start taking pictures a little in front of the scene, and continue taking them until you've focused past the scene. From time to time just check the viewfinder or lcd screen to see where you are. Once you see that you are thru the scene, that's when you stop pressing the shutter.