Nikon D200 focus fault

[cowasaki]

I was working yesterday and taking some pictures of walls outside and in an underground car park. It was maybe 9pm but still reasonably light. I had the 18-55 non VR lens on the D200 as I forgot to pick up the normal lens but I have been using this lens for a week or more. I also had an AFS 105mm f2.8 and SB600. Due to the light I was using the SB600 and ISO was at 1250. Everything was working yesterday and picture quality was not the main concern.

For some reason I was having problems getting the camera to focus especially on darker patches. The camera was finding it very difficult to focus even though I have taken pictures with it in far darker conditions.

I had my assistant standing next to me pointing a bright torch at the focus point and this seemed to be helping although I had to chimp most pictures to check them.

I eventually finishing and returned to base. Whilst sat in the canteen which was perfectly well lit the camera would only focus lock on the lights, not even white objects. It did try and focus but just hunted and stopped in an unfocussed position. I went through all the settings that I could think of like the focus assist light being on and stuff like that.

Well this morning I tried again at home and it was not focussing again but after doing a full reset "+/-" & "QUAL" the camera seems to be focussing again!

Very strange!

 

[Arkady]

Might just have been grubby contacts or a bit of fluff somewhere?
I've had this on occasion when I used to use D2x bodies with certain lenses: wiping the contacts with a cloth and doing a re-set usually sorted it.

Did it do this with the 105mm as well, or just the 18-55?

 

[itsdavedotnet]

sounds like it wouldn't have affected this, but in future, when working in dark places with a nikon flash oncamera, set and lock to centre AF point, and AF-S autofocus mode, and AF-ILL on on your sb600, and it gives off a very useful red grid to help focus

apologies if that was grandma and eggs...

 

[cowasaki]

Might just have been grubby contacts or a bit of fluff somewhere?
I've had this on occasion when I used to use D2x bodies with certain lenses: wiping the contacts with a cloth and doing a re-set usually sorted it.

Did it do this with the 105mm as well, or just the 18-55?

Well I tried to clean the contacts yesterday and blew it out with the rocket blower but it didn't help. The 105 did exactly the same thing and it still wasn't working this morning.

THEN when I reset it it started working so it must have been a software fault. I was sharing the information about my problem in case it happens to someone else but I found it VERY strange.

 

[cowasaki]

sounds like it wouldn't have affected this, but in future, when working in dark places with a nikon flash oncamera, set and lock to centre AF point, and AF-S autofocus mode, and AF-ILL on on your sb600, and it gives off a very useful red grid to help focus

apologies if that was grandma and eggs...

It's useful information to add to this thread for people having problems but it wasn't down to that strangely it seems to be a software fault. I take images in far mirkier conditions without problem normally and use the flash's assist light.