canonian wrote:Is there an optimal value for shift XY ?
Is it better to choose a lot of rocking images at small shift to refine the choice for left/right and create a good looking stereo image?
I've tried calculating from theory, but I gave it up because the results didn't seem reliable enough to be worth the trouble.
So as a practical matter, yes, it's better to try a lot of values and see what works best for your situation. Once you find a value, that same value will work well for other similar stacks.
What I usually do is to set Image Pre-sizing to a fairly small value like 25%. That will run a lot faster than 100% while still giving me more resolution than I need to evaluate the separation. Then I'll run a sequence of 11 frames from -5 to +5. When they're done, I'll poke through the set using Stereo > Start Preview until I find a separation I like. If in addition I like the images I already have, then I'll quit. Otherwise I'll change Image Pre-sizing to make bigger images and run two more frames at the separation I liked best, or some intermediate value if I think I can do better. Generally I end up using something around +-3, but it varies by magnification, aperture, and the nature of the subject.
--Rik