Weird focusing problems with the Nikon F5

[p.giannakis]

Hi everyone,

I recently bought a Nikon F5 in very good condition. when i put the 28-70 (type "D") on the camera, the focus is always spot on. When i use the older AF 50/1.8 (not "D"), the camera cannot focus on infinity. It will focus on any other distance but not infinity,
I put on the F5 some older Nikkors, a 50/1.8 E and a 28/2.8 AIS and again the camera will not confirm focus on infinity.
All these lenses work well on the F90x and the F4s.
Any idea what is happening?

Regards,
Pan

 

[nobbylon]

Pan,
will it hand focus on infinity with the af 50?

 

[nobbylon]

check the central focus point is active, not continuous and single focus point.

 

[nobbylon]

clean the focus screen contacts and confirm it highlights the selected focus point

 

[nobbylon]

you could also check your custom settings are at their defaults by pressing bkt and csm under the rear flap to do a full reset

 

[p.giannakis]

Thank you for your suggestions, i tried them all but they didnt seem to work.
What i noticed thought: It feels as if the AF-motor is trying to rotate the lens past the infinity point. When i assist it with my hand, it gives the focusing light, the moment i let it go, it loses focus. this is the case also with the E-series and 28mm lenses.
No such problems with the newer zoom lens though that seems to focus correctly at all focal lengths.

 

[nobbylon]

ah in which case it's a mechanical focus link problem if it will focus with assist on the older D type lenses. It may have grime or some damage on the linkage in the bayonet mount.
If it were mine i'd gently work the focus back and forward by hand but never against the motor.
hopefully it will free off otherwise it needs the bayonet cover coming off and investigating.

 

[p.giannakis]

otherwise it needs the bayonet cover coming off and investigating.

I suppose you refer to the lens' bayonet cover - not the camera's.
I am just wondering why does this lens still work well on the F4s and the F90x....

 

[nobbylon]

Ok I forgot that. Check that the focus screen is an F5 screen and seated properly. So it can't be the lenses and no I meant the cameras bayonet cover as I think it's to do with the screw gear in the camera.

 

[Fraser]

I found the same problem with a 35-70 2.8 afd on Nikon d1 put it down to both the lens and camera were very well used!

 

[p.giannakis]

Just for the record, I tried two 50mm lenses on my local photo shop, one D and one non-D version and both worked fine on the camera. I traded in my old lens and bought the "D" one.
So it was the lens to blame.