The Repro-Claron is similar to the venerable dialyt formula. Other such lenses, like the Ektar 203mm f/7.7 usually work well for 5x7. The Ektar was my favorite lens on 5x7, and permits increased movements on 4x5. I now prefer it with 4x5 backs on a couple of B&J 5x7 cameras for convenience in printing and scanning negatives.