“Overlap” what is it?

“Overlap” what is it?

I found that this simple term have different meaning for us.
This is not about optical/physical overlap.
Focus brackets have 100% optical overlap. Or in turntable scan we can see 100% of object in all frames.

In photogrammetry overlap have a bit different meaning. It’s about difference in visible points on scanning surface.

So if we scan flat wall and see 1m of it on image, and move camera 20cm side, than this is 80% overlap.

And again, this is not about 20cm difference, this is about 80% of points one both images are identical.

For turntable scan, same. If two frames share 80% of identical surface points this mean 80% overlap.

And finally focus brackets: if you see in one bracket only far parts of object in focus and only nearest parts on another bracket, this mean you fucked your scan because overlap near Zero for this brackets. They do not have any identical points that can use photogrammetry software for its work.

That’s all, folks. ;)