Nikon D40/35mm f/1.8 lens focusing problem

[krb2g]

I'm shooting a Nikon D40 with an 18-55mm, a 55-200mm, and a 35mm lens. We're currently at the beach, so I'm dealing with humidity issues. Generally, I set the camera outside on a covered porch when I wake up, and by the time I'm ready to take pictures it's good to go. Last night I had the 35mm f/1.8 Nikon lens on the camera and it worked fine. This morning, I changed lenses, used the camera for some other stuff, and then changed back to the 35mm lens. While the camera passed through indoor areas (from the front door to the screen porch), it was always kept either outside or in the car. As I kept using the camera (on the beach), I noticed that the pictures were getting softer. The camera did focus when I put something nearer that would require it to change focus, but it was not sharp. As soon as I got off the beach, I tried my other two lenses. It was very clear that those two lenses were both focusing correctly. All three lenses had been with me (in the same conditions) for hours. Is it possible that the 35mm has some condensation that's affecting its AF ability? Or has it been broken somehow? I'm planning to keep trying the 35mm to see if I can get it to work. When I get home, I'll take it in to a local camera shop. Any other suggestions? Thanks for any help!

 

[Gianna'sPapa]

Your description reminded me of a condensation issue I had on my last visit to Florida. I would try to get all the lenses in a controlled environment and do a test.

 

[photo_chick]

Is it sharp when you manually focus?

 

[krb2g]

It wasn't sharp with manual focus either. When I looked at it more closely today, I noticed the UV filter was dirty. Took it off and it focused fine. So basically I feel like an idiot. Thanks for your help!

 

[photo_chick]

Glad it was an easy fix!