Author Topic: Calibrate individual AF sensors?  (Read 9000 times)

Frode

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Re: Calibrate individual AF sensors?
« Reply #15 on: December 06, 2016, 07:26:11 »
I used a D4s (not a D4) for almost two years until I replaced it with a D5.  Never, but never I got AF problems with the D4s. And I'm working in quite challenging AF conditions (action/sport).

Good to hear!

Most likely it's the characteristics of the 50mm that cause the problem... The AF is not reliable in tungsten when using the crossensors, in my case.

Erik Lund

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Re: Calibrate individual AF sensors?
« Reply #16 on: December 06, 2016, 08:01:29 »
Are you using filters? if so remove them. Stop down for more dof or choose another lens :)
I have only had issues like that with CPL or ND filters,,,
Erik Lund

Frode

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Re: Calibrate individual AF sensors?
« Reply #17 on: December 06, 2016, 08:58:42 »
Are you using filters? if so remove them. Stop down for more dof or choose another lens :)
I have only had issues like that with CPL or ND filters,,,

No, I'm not using filters (have a POLA- filter, but have'nt used it for a long time).

Hmm, a bit embarrassing, but the problem seems to end when stopping down from 1.4 to 2.5! Why?

Good to know, but not pleased that I have this "problem" in the area 1.4- 2.2, because that's my most used apertures (portraits).

Anyway, thanks for the tips 🙂! One step further 😊.


Bjørn Rørslett

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Re: Calibrate individual AF sensors?
« Reply #18 on: December 06, 2016, 09:28:04 »
There could be some issue with chromatic aberration under tungsten or fluorescent lighting. And/or the lens has a slight focus shift when stopped down, a common trait for fast lenses.

Frode

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Re: Calibrate individual AF sensors?
« Reply #19 on: December 06, 2016, 10:24:40 »
There could be some issue with chromatic aberration under tungsten or fluorescent lighting. And/or the lens has a slight focus shift when stopped down, a common trait for fast lenses.

Thanks once again! I think I'll accept this as the cause of the problem 🙂.

Mongo

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Re: Calibrate individual AF sensors?
« Reply #20 on: December 06, 2016, 10:47:16 »
Mongo has used his D4s for a couple of years now and does not seem to have this problem. Used with wide angle to 600mm lenses. However have  only ever used single , 9 point and 21 point central focus sensors. All lenses used on this camera are AF fine tuned to the centre sensor.

One really interesting thing was with the D800. Mongo was unlucky enough to get one of the early bodies that had the notorious left sided focus issue. Mongo was so unhappy with it that he took it back to Nikon 3 times in quick succession to get it "fixed". Finally on the third attempt (after getting the appropriate software from Europe/Japan - not sure where but was from over seas), Nikon said the software finely calibrated each AF point on the sensor. Not sure if this was just "BS" trying to convince Mongo that they had done a good  job. However, the D800 came back working better and more accurately than ever and better than any other D800 Mongo has used. So, Nikon may actually have a tool to fine tune individual AF focus point if what was told to Mongo is to be believed. Certainly, the result was outstanding.

Pity Nikon sold Mongo a defective new D800 to begin with and also a pity it took Nikon 3 attempts to get it right.

Not sure if you can make enquiries about the software used to correct the D800 issue and see if it is also adaptable to your D4s issues. Best of luck.


Erik Lund

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Re: Calibrate individual AF sensors?
« Reply #21 on: December 06, 2016, 11:18:40 »
Nikon doesn't BS you.

They calibrate each focus point. Not the same as AF fine tune,,,

Yes the service centres had the wrong software where there was an error. They where waiting for the correct software to do the right calibration.
Erik Lund

Mongo

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Re: Calibrate individual AF sensors?
« Reply #22 on: December 09, 2016, 04:26:14 »
Nikon doesn't BS you.

They calibrate each focus point. Not the same as AF fine tune,,,

Yes the service centres had the wrong software where there was an error. They where waiting for the correct software to do the right calibration.

good to have this confirmed by you Erik. No offence to Nikon but Mongo trusts you more than he does Nikon.

In that case, the original poster could theoretically have his problem fixed and worth making the enquiry.

Bjørn Rørslett

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Re: Calibrate individual AF sensors?
« Reply #23 on: December 09, 2016, 06:59:37 »
I can confirm Erik's statement. I do have witnessed the procedure in persona.

Can also confirm in the case of the D800, Nikon repair facilities had some teething problems relating to the actual test rig and software. These issues necessitated repeated adjustments in the first months of the D800 production.

Akira

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Re: Calibrate individual AF sensors?
« Reply #24 on: December 09, 2016, 13:33:44 »
The calibration at Nikon service solved the AF accuracy problems on my D7000 I used and D750 I'm using now.  Since the calibration, I've never been in need of turning on the in-camera lens calibration function.
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