Df calibration?

[chris dees]

I got myself a nice, low mileage Df (8 months old and less than 8000 clicks).
After testing it every lens needed a AF adjustment between -15 and -20
24G, 58G, 85G and 300PF and I didn't tried my F4 zooms yet.
Should I send it in for AF calibration now it's still under warranty?

[Bjørn Rørslett]

Strange. I have used a handful of Df units by now and never had any need for AF fine-tune with any lens (not counting the 105/2 DC which shouldn't have been launched as AF in the first place due to its DC feature).

I suggest you let a certified Nikon repair facility check the camera for any problems such as mount being warped, angle of main or secondary mirror out of alignment, etc.

[chris dees]

It's strange, the guy I bought it from used it with a Sigma 35 art and that one was spot on.

I guess I'll have a ride to the service centre.

[Erik Lund]

Chris, maybe you should take a step back and have a look at your focus test one more time...

Are you square and level on the target etc. you know there are many possibilities for small mistakes...

Have a little fun shooting it for normal targets

I have never had to adjust any of cameras for my AF lenses...

That his Sigma was dead on is sadly not a quality check though so you might have to let it go in...

[Akira]

To me, it's not all that surprising.  My AF-S 35/1.8 ED had to be fine-tuned to -20 on my D7000, but after I had my camera calibrated (either on the hardware or on the deeper level of firmware) at Nikon service, I don't need to use the fine-tuning function anymore.

I think it's worth having your camera checked at the proper authorized Nikon service.

[chris dees]

Thanks, I'll have a closer look this weekend.
Those lenses need only a little adjustment on my D810

[Jan Anne]

Congrats on the Df Chris, didn't take long for you to get one after we talked about it during drink night

[chris dees]

Congrats on the Df Chris, didn't take long for you to get one after we talked about it during drink night

I started negotiations before I got sober.

[chris dees]

I did the focus tests again and with more or less the same results.
                         D810    Df
24/1.4G                  -   -20 (or more)
58/1.4G                  +5   -20 (or more)
85/1.4G                  +3   -17
300/4.0E              -   -12
70-200/4.0G         -   -
Tamron 150-600   -   -
The 24, 58 and 85 were not sharp at infinity, the other lenses are razor sharp

[Bjørn Rørslett]

Something is out of alignment on your Df. My hunch is the angle of the secondary mirror.

If you focus manually are the images in focus where they should be?

[chris dees]

Manual (although not my forte) as well as Live-view focussing is not a problem.

I'll contact the service center tomorrow and make an appointment for AF callibration.

[stenrasmussen]

I agree with Bjørn about the sub-mirror. I am collecting my almost new (1500 clicks - of which I've added 800 myself at an earlier occation when I met up with Bjørn las May). I hope my sample behave AF wise...although MF will be my preferrred operation.

[Martin Zimelka]

I got myself a nice, low mileage Df (8 months old and less than 8000 clicks).
After testing it every lens needed a AF adjustment between -15 and -20
24G, 58G, 85G and 300PF and I didn't tried my F4 zooms yet.
Should I send it in for AF calibration now it's still under warranty?

Under what light source are you shooting your test targets?
Many cameras will tend to back focus under tungsten or warmer light sources when used in combination with fast lenses.

This was particularly prevalent with my D700 and lenses such as the AF-D 85/1.4. I have AF fine tune values for daylight (virtually zero) but by contrast rather large AF fine tune values set for shooting events. Manual focus and Live View were all good.

I always do my AF-calibrations outside in broad daylight.

My D700 and D800 both behaved the same under different light sources, however, my D810 does so to a lesser degree.

[stenrasmussen]

What hmzimelka said.
Additionally it can be useful to do two sets of AF tunings, one for daylight and one for incandescent light. A little note taped on the side of the battery or SD card can help one's memory of what to dial in.

[Erik Lund]

That's right, we have seen that before, thanks for the heads up!