D810: AF went completely down

Recently I purchased a D810 and an AF-S Nikkor 50mm 1:1.4G lens. All worked well during weeks till suddenly the AF was shot down. After studying for hours it worked again, without knowing the reason why. Then AF shot down once again. Not even focusing light is turning on in dark circumstances.
Of course side switch is in AF position, not in M position.
On the lens switch is in M/A position, not in M position.
Focusing mode is AF-C, but AF-S doesn't work either.
One suspect: It occurs when I change to “live view”, especially video. Video is not my main subject, but wanted to try it.
Maybe unwillingly y changed some other affecting settings.
Already tried to reset default settings.

It is different to the problem of our colleague who posted “HELP! My D810 is having auto focus issues”. I had this problem, too. But a look to the manual saved me. But, very theoretically, it is the same problem. Is it possible, that the focusing point goes so out of range, that focusing is lost? If so, how to reset it?

Someone can help before recurring warranty?
Thanks in advance

I don't really understand the problem but I just checked mine and regardless if I shoot viewfinder, live-view (film or photo), the moment I push the AF-ON at the back, my lens will focus.

The focus methods are different if you shoot live or viewfinder but in my case, all works as it is supposed to.

If yours doesn't, first try another lens to check whether it is the cam or lens.

As J-see did, I just checked mine and all's well regardless of live view Vs viewfinder.... sorry I can't shed any light on the problem.
Puzzling one ????
Maybe try a total "reset" of the camera and start over... may be worth a try (a bit like turning your computer off for a few minutes and starting it up again - sometimes clears the problem)

cheers

Thank you very much for comments. Indeed it’s very strange. Conclusion: it’s not Life View that causes the problem.

Good news: recently I went out for a family shooting. Resigned I put the switch on the camera to M (not on the lens, that has to stay on M/A). After some shots I became aware that the focusing aid works again (It didn’t before). So I switched back to AF, and it worked perfectly. It seems, there is a Jinn in the camera, who decides from time to time if AF should work or not. Same occurred already in other occasions: part of the event AF didn’t work, then suddenly it worked again.

I assume, that the AF aid in the manual position works without the lens. That means, the fault is in the camera, not in the lens. Most probably I’m touching unwillingly some bottom which puts AF out of effect. But which one? It’s not the AF-switch on the left side of the camera, that is already proofed.
May be, it’s a physical defect. But when I go to the Nikon service, the Jinn decides that AF will work and I even cannot explain my reclamation to the service people.

As recommended by you, would be a good idea to see, if the same phenomenon happens with another lens. Unfortunately I have just one lens, the AF-S Nikkor 50mm 1:1.4G. That is part of my philosophy. Instead of a zoom I make a recut of the picture: cutting a 4[SUP]th[/SUP] part of a 36 megapixel image leafs me a 9 megapixel image. Today there is no affordable screen on the market to reproduce a 9 megapixel image. 4 mp are the maximum for a screen. And cutting the image gives me more possibilities to compose the picture in an dynamic environment.

With this lens in 1:1.4 and A mode (priority on diaphragm) good focusing is crucial for the small depth of field, but may be more difficult for the AF.

I’ve tried different light, different patterns, different distances. When the Jinn say no, no chance. Then suddenly it works again, with the same light, patterns and distances. So far I couldn’t find the way to convince the Jinn in a certain moment, that AF would be helpful. If I find the way, I will post it here.

What button do you use to focus? If you use the release try using the AF-On at the back or eventually configuring the cam to focus with another button. That way you can check if there might be a bad contact in the button you're using now.

I had a similar issue last week with my D750 while using the remote app on my phone for some self portraits. It focused just fine for a bit but suddenly I couldn't get it to focus at all. I took it off the app/live view mode and still couldn't focus. I even cycled power with no luck. But once I removed and remounted the lens, all was good. It was with a Tamron 70-200mm f2.8. Haven't had an issue since but I haven't used the remote app again either.

Good idea! I use both. Even change of configuration as you describe didn’t help.

J-see said:

What button do you use to focus? If you use the release try using the AF-On at the back or eventually configuring the cam to focus with another button. That way you can check if there might be a bad contact in the button you're using now.

Click to expand...

Good idea! I use both. Even change of configuration as you describe didn’t help.

Osantacruz said:

I had a similar issue last week with my D750 while using the remote app on my phone for some self portraits. It focused just fine for a bit but suddenly I couldn't get it to focus at all. I took it off the app/live view mode and still couldn't focus. I even cycled power with no luck. But once I removed and remounted the lens, all was good. It was with a Tamron 70-200mm f2.8. Haven't had an issue since but I haven't used the remote app again either.

Click to expand...

I tried that, too. Not just once, several times I removed and remounted the lens. It didn’t reestablish AF.
When AF is working well, removing and remounting doesn't reproduce the failure, means, AF is still working afterwards.
In deed there is a very small gap with the mounted lens: I can turn it a little bit, a very little bit, even if it is locked. Is that normal? But that has no effect on AF working or not.

At the moment AF works even in very complicated situation, through reflecting windows and mirrors:
Nikon Image Space: NIKON IMAGE SPACE
The other day it didn’t work, I think, due to the very difficult atmospheric conditions, mist with very high radiation. I had to focus manually.
I needed a lot of software to have some color in the pictures:
Nikon Image Space: NIKON IMAGE SPACE
But, back at home AF worked perfect again.

So: My prime suspect is: some unwillingly touched button shuts AF down. Which one?
Ricardo Zettl

Is it possible, that too much light turns AF off?
Another day AF didn’t work and I had to focus manually. There was so much light that with ISO 64 and the shortest exposure I had to reduce diaphragm to take pictures. AF stood ineffective.
Nikon Image Space: NIKON IMAGE SPACE

Today I went to the Nikon Service Center and just at that moment AF failed. They declared it a lens issue that will be revised.
So this discussion came to an end.