Lens Fogging Help

This morning I went to a new wetland park near my house to investigate and shoot some birds. Not knowing what to expect I just took along my 300/2.8 with a 2X. Turns out I could have used the 500/4 real well.

However, my front glass on the 300/2.8 fogged up real bad. I tried using a dry t-shirt material to clean it off before shooting, but it came back almost instantly. I'm thinking this must be because the lens had been in 74-degree air conditioned house, 69-degree air conditioned truck, and then opened in 84-degree air at 90+ percent humidity. Short of leaving the lenses in the truck overnight so they are closer to the ambient temperature when I take them out for an early morning shoot, is there anything that can be done about this?

Thanks!

Kelly

This is the reverse of what happens in the winter. I leave my gear out in my truck pretty much year round.


Kent in SD

That's happened to me before when I went from a/c car to the beach. It seems it just has to adjust to the temperature awhile. I don't leave my gear in the car mostly because I don't want it stolen. I also wonder if extremes of temperature would damage gear consistently left in a vehicle?

Yes, it's condensation. The visible condensate on the lens is annoying, the stuff you don't see inside the camera has the potential to ruin the morning. Seal the camera and lens in a big zip-lock back and let them reach ambient temperature before use. My experience with this sort of this was shooting in butterfly houses, there, a 1/2 to 45 minute wait didn't matter. You might be better off letting the equipment spend the night in the trunk (if you have a garage).

Pete D.