[MF3D.FORUM:977] Re: Stereo Pro with Wide Angle Lenses

[Greg Erker <erker@xxxxxxxxxxxxxx>]

>Gee, I'm not sure. The focus only changed a few mm, so I suspect the
>attachment changes the nodal point. I'd say you get 30-40% more in the
>picture. If I work out the actual percentage and multiply it by the
>standard focal length, will that give me the new one?

  If it's marked as 0.7x or whatever then
you can just multiply that by the lens FL.

  If it's unmarked you could compare the
ratios of the angles of view (with and without)
then use an angle of view calculator:
http://www.mat.uc.pt/~rps/photos/angles.html
to figure out what the effective lens
FL must be.

Greg