Dealing with Condensation on Supertelephotos

As we enter the winter season, at least in the U.S. midwest, again I was wondering if there are any new, or old faithful, ways of dealing with condensation on supertelephoto lenses when returning home from a cold day in the field. Its pretty easy to pop a 300 F4 in a ziplock bag for awhile but how do you deal with 500 and 600 F4's with or without attached camera bodies? Does wrapping a trash bag around the whole rig work or is it better to just leave it alone and let it dry off on its own? I've even thought of throwing the rig in a giant, insulated cooler for a few hours. Thanks for your consideration and I'm looking forward to hearing from everybody.

Hi Danny,

I use a thin garbage bag, then I try to squeeze as much air out of it as possible when the camera and lens is inside it. If I can't get most of the air out I will suck the rest out. Then I throw a twist tie on it.
It works every time up here in the great white north eh!


Michael Bertelsen
www.algonquinparkphototours.com

Hi Michael: I was beginning to think nobody was going to reply but I knew that everybody at BPN didn't live in Florida. I've been doing what you suggested but wasn't sure it was enough. I'll continue with that program. Thanks again because this bothered me all winter last year but I could never find good info by google searching.

you can get large ziplocks as well, I know walmart carries them and they are near the garbage bags I believe, they are made for storing clothing etc I have not used them for condensation but I keep one in my bag in case I ever get in a big rainstorm to stick the 500 in

Thanks Jamie, I'll definitely check on that. I suspected there might be some giant ziplocks out there but never looked. As usual, Walmart satisfies all of my shopping needs!

walmart doesnt have any good camera gear :p lol

but yeah check it out, I believe there are 3 or 4 large size ones http://www.amazon.com/Ziploc-Pack-He..._bxgy_hg_img_c

Danny,
Super telephotos are weather resistant. I just put the boot on the front, and if there is no camera on, I put the back lens cap on. If I've come in from a trip, the lens is in a backpack and I leave it there for a while. But if I come in from just outside I just bring it in and set it on a table or shelf. I do a lot of astrophotography and bring the lens in from the cold often. It's never been a problem. But then it's pretty dry here in Colorado.

Where I find more of a problem is in hot, humid environments. There you leave a cold air conditioned environment and want to open the lens up in a humid environment. I let the lens warm up before opening it up to use.

Roger

Thanks Roger. It sounds like I don't need to be obsessing over it too much. Before I started using a trash bag, I would often just wrap a polar fleece around the rig to keep the warm air in the house off of it for a while. I never worried too much until I invested the $6000 in the 500F4.

Thanks again to everybody - you have put me at ease.

Since we are talking about wrapping up lenses, the biggest problem I have is not bringing the lens in and out of warm/cold environments, it is focus shift during a long exposure, particularly with my 500 f/4. I'm talking over a 20 minute period or more. So I'm looking for a good insulating blanket I can wrap around the lens, perhaps with velcro. If anyone knows of such a thing, let me know.

For reference, here is a 28 minute exposure of a galaxy with the 500 f/4:
http://www.clarkvision.com/galleries...-v1.6-700.html

As temperature changes through the night the lens shifts focus, being a metal tube, due to expansion/contraction. A star can be nicely focused and cover one pixel and 20 minutes later, focus shifts and the star covers 9 pixels. The stars can be so faint, one autofocus does not work, and the live view is not good enough either. So reducing temperature drift seems to be the only solution.

Roger

I like to take moon pictures (here) and had issues with lens fogging when coming out of the house to take pictures. My solution was to simply put my 600mm (with it's storage box) in the garage on the day I was expecting to use it. That let the lens slowly get close enough to outside temp to stop the lens from fogging.

Danny,

The night before, I put my 500mm in my Lowepro and set it in the garage. It slowly achieves outside temperature, or close to it throughout the night. When I come back from the shoot, I just put it back in the closet in the Lowepro. Once again, it will slowly reach ambient temperature with no condensation problems.

Enjoy that glass!

Colin