Re: stitching focus stacked images
- --- In PanoToolsNG@yahoogroups.com, "David" <dburton97128@...> wrote:
>Stitching & merging macro images is conceptionally different to stitching panoramas in that the final image has orthographic projection, not equirectangular or rectilinear. Stitching is only possible if your source images either have no depth (the usual macroscopic "panoramas"), or are orthographic themselves.
> I have a macro photography project I would like to shoot as focus stacks and then merge and stitch the images together.
> The problem with this is that the camera is typically moved while keeping the focus setting constant to shoot the focus stack. This then complicates the stitching because parallax is introduced as the camera is moved.
Orthographic images can be taken with telecentric lenses as has been mentioned in this thread. Another, simpler approach is focus stacking using large aperture lenses set to constant focus. The camera is moved with respect to the object. The DOF region must be very narrow (aperture open) for this. You sweep this narrow region (with constant magnification) through your object, while fore- and background dissappear. That means all object distances are subject to the same magnification, which results in an orthographic focus stack, and which then can be used for stitching.
I did a few experiments along these ideas recently using a x4/0.1 microscopy lens to test new features of PTStitcherNG, and it worked quite well for my testcases. I will post an example if it makes it into the next PTStitcherNG release.