Nikon D800 AF trouble

[RalphLambrecht]

really strange... I have several AF lenses for this camera and all work but my 50mmf/1.4 refuses to autofocus with the D800. Is there an easy check? Did I do something stupid? Just tried my 35mm/f/2 and it works just fine. I previously had an MF lens mounted. Could that have screwed up something?

 

[randyB]

Is your AF 50mm f/1.4 screw drive or is it a AF-s ? If screw drive, perhaps the drive shaft has gotten stuck and won't engage. If it is AF-S then maybe the contacts are dirty.

 

[RalphLambrecht]

Is your AF 50mm f/1.4 screw drive or is it a AF-s ? If screw drive, perhaps the drive shaft has gotten stuck and won't engage. If it is AF-S then maybe the contacts are dirty.

Andy, it's a screwdrive and I think, a bad coupling was indeed the issue. I took the lens off and mounted it again a few times, watching for proper seating, and now it works just fine. many thanks

 

[RalphLambrecht]

Andy, it's a screwdrive and I think, a bad coupling was indeed the issue. I took the lens off and mounted it again a few times, watching for proper seating, and now it works just fine. many thanks

I'm now wondering if this was caused by the lens I just used before. That was a non-AF Mikro Nikkor, which does not have an AF coupling. Could this be caused by the AF drive on the camera getting stuck somewhere on the back of the non-AF lens(and possibly ruining my lens)?

 

[reddesert]

The AF screwdriver on Nikon AF bodies is spring loaded. If you mount a manual focus lens, the lens flange pushes the screwdriver back into the body, whether the body is set to manual or autofocus. No damage to either lens or body should occur.

The MF/AF switch on the body (which usually says M/S/C), retracts the screwdriver to disengage the AF drive from an autofocus lens.

My guess is that on your body/lens that wouldn't autofocus, either the screwdriver or the lens slot that receives it was slightly out of alignment and they weren't engaging. If this happens you can try examining the driver and slot to see if anything is out of alignment, and gently poking the driver and slot to make sure they are moving freely and in the proper position - the slot should be only a tiny bit recessed from the lens mount flange.

 

[RalphLambrecht]

The AF screwdriver on Nikon AF bodies is spring loaded. If you mount a manual focus lens, the lens flange pushes the screwdriver back into the body, whether the body is set to manual or autofocus. No damage to either lens or body should occur.

The MF/AF switch on the body (which usually says M/S/C), retracts the screwdriver to disengage the AF drive from an autofocus lens.

My guess is that on your body/lens that wouldn't autofocus, either the screwdriver or the lens slot that receives it was slightly out of alignment and they weren't engaging. If this happens you can try examining the driver and slot to see if anything is out of alignment, and gently poking the driver and slot to make sure they are moving freely and in the proper position - the slot should be only a tiny bit recessed from the lens mount flange.

Thanks for the advice I'll check!