Backfocusing issues on D4

[ichiu]

I picked up a well used D4 and it is backfocusing on all the lenses I have (AF 50mm f1.4, AF 55mm f2.8 and Tamron 90mm f2.8. I've tried the AF micro adjust and -16, -17 seems to work for close distance object, but when I took the lenses out to take some random shots, even at -16 and -17, even -20, the lenses backfocus. When I shoot in live view, I have no issues, it is all sharp. It is only when I focus through the viewfinder. The picture through the viewfinder is tack sharp. Is there another adjustment, say of the focus screen? Any help is greatly appreciated.



this is a 100% center crop. Focus is on that thread.





picture taken in live view

 

[AWG_Pics]

I recently had similar issues with my D5. So, after reading the AF fine tune section of the manual, I realized I was testing AF wrongly. I reset everything to its' unadjusted condition, put the camera and suspect lens on a tripod and waited until a sunny day and shot a well defined subject hanging perpendicular to my camera/lens. Result: No AF issue at all with this set up. Good light and a proper target are important.

I see you used F 2.0 which is a very thin in-focus region. Try again with a similar set up I used -- at least you will have an accurate outcome to further assess your focus issues.

 

[Simon Stuart]

I’d say you have an issue in the AF optical path, likely the mirror position needs adjusting. A service centre should be able to sort that out, I doubt parts are needed.