F4 Focus Problems...Advice Most Welcome
I bought a used F4 a while back. I had a problem with the MB-20 battery supply in that after taking a shot the red alert light would flash and I would then have to turn it off and on before it would fire again. This would not happen with the MB-23 power supply. I even sent it to Nikon NJ for a CLA and to check the alert light issue and it was returned after some cryptic repair explanation. But two things appear to be still happening:
1) When I try and focus using any lens, the split prism never aligns perfectly regardless of the lens used though the green light comes on.
2) When test firing (without film) in P and S modes the red alert light comes on after each shot. In A mode this doesn't happen. This happens using either the MB-20 or MB-23 power packs.
Is there any reason that the power pack would cause any of these problems. Are there an adjustments that I can make to the focus? Should I bother sending it in for repair again? I would really like to use this camera and am rather disappointed.
Thanks for you advice,
#2. "RE: F4 Focus Problems...Advice Most Welcome" | In response to Reply # 1Sat 17-Nov-07 11:54 PM
Within minutes I received a reply on the Photo.net Nikon forum to put in the original B type focusing screen and try again. I had bought the K Type screen after reading somewhere that the F3 screens could be used in the F4. Seems not the case. The F3 K-type screen is slightly thinner than the F4 B screen (now that I place them side by side) and has red lettering rather than white. With the B screen in place all seems fine, plus the red alert light problem has stopped. I still don't understand that relationship. What surprises even more is that I sent this camera to Nikon for a CLA with the K screen to see what the red alert light problem was about and they never mentioned the problem that I had the wrong screen in place. That's doesn't make me very confident with their service.
#3. "RE: F4 Focus Problems...Advice Most Welcome" | In response to Reply # 2jimmomary Registered since 14th Jan 2005Sun 18-Nov-07 01:03 AM
Also, for general info, the alert light will blink if 1. the camera is on, and 2. has no film and 3. with the ASA/ISO set to DX. (all 3 conditions at one time). While it is blinking no exposure in any mode can be made. To be able to dry fire an unloaded camera in DX, the camera back must be open. To "properly" dry fire, any film speed except DX needs to be set.
#4. "RE: F4 Focus Problems...Advice Most Welcome" | In response to Reply # 3Sun 18-Nov-07 01:16 AM
Thanks Jim. Camera not set to DX. I had the alert light problem also when film was in the camera with the MB-20, though I'll have to test that again with the B screen back in. The problem has disappeared with both the MB-20 and MB-23 power supplies after putting back the B screen. I can fathom why the D3 screen affects the autofocus if it's slightly thinner, but it's curious to me how this affects the red light alerts which, I thought, was related to film transport issues. I've searched the net and there's very little about F3 screens and use in F4, or the apparent fact that F3 screens are printed in red and F4 in white.I guess it was just my mistake in seeing somewhere that F3 screens would work.