Talk:Strong focusing

I think that this image has wrong filed lines...

http://upload.wikimedia.org/wikipedia/commons/e/ef/AGFocus1.gif

Looks OK to me. What do you think is the problem?- (User) WolfKeeper (Talk) 01:07, 18 July 2008 (UTC)

Weak focusing

In the introduction, I think the part about weak focusing, it should read: [...] the principle that nearby circles [...] only intersect TWICE per revolution. OR: [...] only ONCE per half-revolution.