Tom Reese wrote:
Jostein wrote:
Quoting William Robb <[EMAIL PROTECTED]>:
Remember when doing this sort of picture that with the secondary
exposure, the focus needs to be closer, not farther as compared to
the first one.
That's a rule of thumb I have worked by, but the exact reason why
escapes me...
When you focus closer the out of focus image gets larger. When you focus
further away the OOF image gets smaller. If you want an OOF halo around
the flower then you have to focus closer.
I just went outside and tried this because I didn't think it made much
sense. I was right. It didn't make much sense. The halo does get much
bigger when you focus closer but it also expands when you focus further
away. My new theory is that you should focus closer because it will go
out of focus more quickly and more completely because the DOF narrows in
that direction.
Tom (even I'm wrong on very rare occasions) Reese
