Picking ideal lens and fl, for flat copy work

[Jim Galli]

I tend to take the seat of the pants approach. Dan Fromm gave you the best advice. Longer than you need will solve resolution, mtf falloff, and light fall off. Kenro used to supply a 10 3/4" Goerz copy lens (dagor type) that is simply stunning. Maybe all the modern numbers games would slaughter it, I dunno. Ask the Marlboro Man up on the billboard. In my profession we've yet to do better than a 127 Ektar for painting light on 1/2 frame 35mm film. Before you throw up, think about it. That little cheap tessar will resolve 80lppm in that little sweet spot we need to cover that small film. Just a slightly different approach than leanest meanest I guess.

[paulr]

"Longer than you need will solve resolution, mtf falloff, and light fall off. "

longer gives you flatter performance from center to edge, but all else being equal it will be less sharp in the center than a shorter normal lens. more of a tradeoff than a solution.