Quote Originally Posted by ic-racer View Post
For example a +1 close up lens will be 1000mm focal length. Add that to 300mm you have (which is +3 diopter) and you get a +4 diopter lens. Focal length = 250mm. That may help you or may not.
So, the net effect is that I could stack diopters to give myself a ghetto convertible lens?