John, I don't know why, but the 127/4.7 Tominon as sold in #1 Copal Press for, e.g., Polaroid CU-5 and DS-34, is much better at distance than the MP-4 135/4.5 Tominon. Years ago I bought a CU-5 one for the shutter, tried it out on a 2x3 Graphic, and was so pleased by it that I put it in my out-and-about kit. I can't speak to its usefulness on 4x5, but its great on 2x3.