To do focus stacking in case of moving subjects, it would be useful to have the ability to preset different focus settings and let the camera take the pictures with the different settings in fast succession. Are there cameras with such a feature?
New edit in response to comments to make clear when this is useful.
- Landscape photography. Suppose that the conditions are rather dark and you want to limit the exporure time to about a second due to motions in the landscape (e.g. slow moving waves in the water). This may mean that you need to shoot at F/8 or larger aperture which doesn't give you a lot of depth of field. Shooting again manually and having to change the focus setting is almost impossible to do within one second, but a camera programmed to shoot multiple times at different focus setting should be able to shoot, say few exposures of a few tenths of a second within one second.
- Macro photography. I don't have any experience with this topic, but I've read that one major limitation of doing focus stacking here is due to the motion of the subject being photographed. Like in case of landscape photography, it seems to me that focus stacking should be possible for sufficiently slow motion of the subject and that you would have more room to do this if the camera were capable of taking pictures in fast succession.
Note that the advantage apart from possible overall sharpness (due to evading the diffraction limit) comes from the following fact. The sum of all the the exposure times needed to get everything in focus wen doing focus stacking from a distance x to infinity behaves asymptotically as log(1/x)/x for small x (compared to the hyperfocal distance), while getting everything sharp using a small enough aperture leads to a minimum exposure time that behaves as 1/x^2 for small x.
