Originally posted by biz-engineer That's also what I think. Leading lines (perspective) transverse to the DoF make the subject (part in focus) pop out of the frame.
The stem in that case is a leading line, gradually blurred , creates the 3D effect.
Interesting observation. Overlap works too as do non-perspective "leading" features.
Here is another where perspective might be involved... And couple where overlap is obvious
The 3-D on this one might be enhanced somewhat in post by applying a gradient to make the background "recede".
And one where there are leading lines/features, but without obvious perspective references
It seems there is more than one way to approach this, some of which may be enhanced by appropriate post-processing...give the subject "pop" and do magic to make the background recede.
This thread is providing some grist for the mill.
Steve
(...did some enhancement in PP yesterday that inadvertently worked to create greater 3D effect...
LINK...)