Stacking on the Z axis?

[traveller (Bo)]

Just a crazy thought, has anyone developed a program to allow for stacking on the Z axis?
This method is common in scientific imaging applications to effectively render 3D images from focusing on and exposures on different layers and then build up a 3D image. This is useful for medical, scientific and engineering purposes.
So one could (theoretically) do the same for astro imaging, but would be limited to large, bright and close objects like the sun and the moon and focusing on different “planes” of the object (as opposed to different angles from the same plane). Each “slice” can then be stacked on the Z axis to render a 3D image.
Someone may have already done or tried this, but I haven’t seen it yet.
Maybe it’s just another brain fart.
Bo

[billdan (Bill)]

I don't think that process will work for astrophotography, because we are always focused at infinity.
It works for microscopes because of the limited depth of field a microscope has, where they have to re-focus for different layers of the specimen under the microscope.