Hellos - Some help. I need to pickup a 3rd lens but Im in a quandary. I have 2 lenses for my graflex RB 4x5. One says: "5x7 B&L - tessar 1c 7 1/2" f4.5. The other says: "Kodak Anastigmat 7 1/2" f4.5 3 1/4 x 5 1/2" I am missing the barrel/iris on the tesser. On my speed graphic the kodak seems to have full coverage. Does anyone know the differences of these 2 lenses? TY dw