My Nikon F4s is in trouble. See attachment. Upper frame A mode, middle frame P mode, lower frame M mode. Shot 3 frames each of a scene in "A","P" and "M". "P" underexposes in each frame of the 36exp E6 roll. Comparing F100 and F4s in S mode yields a F4S exposure time which is much shorter than F100 exposure times ( 1,2 and 4 secs tested because you can "hear" it starting and stopping). So my conclusions: 1) matrix meter's fine in viewfinder prism as "A"mode is 100% ok 2) shutter's OK as A and M work fine. 3) "computerised" program and shutter priority are sh.tt. What would you do next? Anyone who's got this problem on his F4/F4s/F4e and got it solved? I'm considering a KEH body without prism to swap the defect body and have a spare one for parts. Any answers and tips welcome! Thanks.