Cold Weather lens problem?

[Stockybod]

Hi all,
I went out today for some snow pics in Chicago. Temp was around 25 degrees, shooting with my D40X and my AF-S DX VR 55-200. Anything above 105, and the auto focus wouldn't work. I was able to take pics in the manual mode. When I tried to auto focus, the focus ring kept spinning back and forth.
Could the cold weather make the lens not to auto focus?
Thanks

[RP Racing]

Probably has some fog on the inner glass the AF sensor picks up on when above 105. I usually let my D70 sit for a few minutes in the cold before taking pics.

[Stockybod]

Thanks Rob,
So you're saying that before you start shooting, let the camera get acclimated to the cold, as opposed to taking it from the warm car and then shooting outdoors right away?
I didn't know if the lens was bad, it was the first time I used it.

[RP Racing]

Basically. Just like wearing glasses. Going from cold to warm and warm to cold fogs glass. Usually cold to warm is worse.

[mn shutterbug]

I've never had a problem going from a warm car to 15 degrees fahrenheit. I've heard the problem is going to happen when going from cold to warm. When I bring the camera in from the cold, I place the camera with lens, inside a kitchen trash bag and don't remove until acclimated to the warmer air.

[WsW-WYATT-EARP]

it could be that the lens couldn't find enough contrast to focus on ... with all the snow i had issues the other day with it too. I agree with what mike said - I never had a problem going from warm to cold - its going the opposite way that causes issues

[another view]

I think Ben is right - I've never had a problem going from warm to cold. Low light and/or low contrast can make it hard for a lens to find anything to focus on. Since it was only at the longer end of a variable aperture zoom, you were probably right on the edge of the camera's ability to "see" focus.

F5.6 is sort of the magic number - lens speeds slower than that (maximum aperture) don't usually work well with AF, so I'm guessing that as you zoomed out and the maximum aperture got closer to 5.6, it couldn't see anything.

[retroactiv]

I know this sounds weird, and takes a lot of cleanup after doing it (taught to me by an VERY old school photographer) and yes I've done it once and it worked and yes it is a pain in the you know what to clean. I only did it because I was in a pinch and it was breaking news in front of my eyes.

Spit on your lens if it is only the outter glass fogging, and wipe it around. Gross but it works, and gives you a bunch of extra work but like I said before if you are in a pinch and have to have that shot now, try it.