Extreme tempatures with lenes help

Hi all Well i made the plunge, and got a new 24-70 2.8 and i love it. Just shot a wedding yesterday with it the pictures came out excellent. But as i was reading the manual, i just love reading manuals (lol) but they talk about extreme tempature diffrece from goign to cold to warm and warm to cold. Well i am in upsate ny and it does get cold here. They say to put the lense in a airtight bag, wich i have never heard of. i have a tamerac pro 12 bag. wich my camera and my lense always stay in. but i am worried about the whole condesation thing. I mean you i go from a warm house out to a cold car in the winter. you know? and vice versa, say your out side very cold winter shooting, then you take you lens of the body put it in the bag why you are out side, how do you guys take care of that stuff? any suggestion woudl be helpful , from very warm to very cold, then very cold to very warm. any help and sugestions woudl be great thanks guys and gals

The "airtight bag" is nothing more than a "ziploc" or "glad" FREEZER BAG. There is NO problem with taking your camera out to the cold !!

Coming in - the warm moist air collects and condenses on your camera. Potential problem with it invading the interior parts of your camera.

BEFORE you come in- put the camera in the zip-lock - close it tight- set it down somewhere inside, to normalize. This might take a half hour or so - don't push it. If you open the bag to soon - ya' blew it !!
Once the condensation is gone from the outside of the bag you should be just fine.

It's the same physics that you see in the summer with a cold glass of ice tea, all of a sudden the outside of the glass is "wet".

thanks for the help, but is that for both the camera and the lens? I mean if you have a body , and lets say a 70-200 2.8 is lens on the end of it the whole thing is not goign to fit in a bag, so do you just take them arpt and put them in serpate bags, one for body and one for lens, and caps on or off? and lastly does the camera bag act as a airtight bag? i ask cuase once a few years ago i was driving down the road saw and accident, hoped out and got sompe pictures and then 20 minues later i just got in to my car, and there was no problem with any wetness or condesntaion. Any more help woudl be great thanks. and thank you so far for the help you have givin.

I bag my camera and lenses separately, only because I cannot find freezer bags big enough for both together.

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Hey Chris-

Bagging your gear in the house and then going outside is a waste of time. You do not gain a thing by doing that. It is a matter of physics. You might however, carry your battery in your inside pants/shirt pocket. Cold batteries just are not as efficient at lower temps.

Also try taking your CF card out of the camera before coming in. That way you can be looking at your photos while your gear normalizes to room temperature. The card has no internal parts to worry about, so you can pop it into your reader right away.

Ya, I kinda figured that going from warm to cold would be a waste, but I personally find that if I am diligent in keeping things in the bags, then there is less chance that I will become lazy and stop storing them properly.

I guess I do it because of the ocd (obsessive compulsive disorder).

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At what tempature do you ahve to start worrying about the fogging of the lense? in farhenhiet i mean, like 30 20 10 degrees? you guys have been so helpful. if anyoen knows please let me know.

wlahc1 - If when you step outside, you see your "breath", it is time to consider bagging before coming in.

However - Lets say you are back at your car, which has cooled off while you were out shooting. I just put everything back in my camera bag why? because everything is "cool" - bag and other gear.

As you drive your car back "home" it will warm up slowly and everything in the camera case/bag will have a chance to normalize. Generally if your camera is "cool" not cold, it will be just fine.

I once went to photograph butterflies in a tropical butterfly house, on a cold wet English day. I took my 100-400 into the warm and left it for 20 minutes and it was still fogged up. It took nearly 40 minutes before I could use it. It even refused to autofocus for a while and that was scary but it was fine when it dried out!
I suppose that this was an extreme case - almost 40 C temperature difference instantly, but you do have to be careful and wait.
Incidentally I don't think that there is a temperature at which you have to worry, so much as a difference between hot and cold. If there is water in the hot air it will condense on a colder surface.

Mark- Classic example !!

Happens here (Michigan) exactly the same way and time line.

Had my 10D w/70-200 f2.8 IS sitting on the passenger side floorboard of my car. Had the air conditioning on. Pulled over for a grab shot of a hawk that just nabbed a rabbit. It was a warm day (mid 80's), my lens fogged up before I could get the shot.