----- Original Message ----- From: "TSHACK" <[email protected]>
> I congratulate you folks who can focus one of these things through the > viewfinder. I pulled out my Crown Graphic, slapped on the reflex viewer, > tried focusing on a light source, tried focusing on a subject outside, and I > really couldn't tell any difference except at the extremes. > > Maybe if I use a loupe. Maybe not. Although I do not recommend focusing of the zoneplate every time you make an exposure, I do recommend you focus it ONCE so you find out (if you wish) the actual focal length of it. To do it, aim your camera to a light source (light bulb for instance) or well illuminated object and focus on the aerial image, rather than on the ground glass. You will be surprised how "good" is the image a ZP produces. And yes, use a loupe. Guillermo
