As a beginner in 4x5 photography I'm getting very frustrated in consistently getting Underexposed 4x5 color slides from professional lab. The slides look like they are consistently 2 f stops or more underexposed!!! This despite experimenting with different exposure settings and two film type, Fujichrome Astia 100F and Fujichrome Provia 100F , and taking color Polaroid's, which come out good and accurate. I also tried two different cameras with different lenses, but the results is always the same dark underexposed film! I will next try a different processing lab, but would appreciate any help and suggestions as to what I may be doing wrong. PS I had no such problems with 21/4 format. Thanks in advance.