Stopping Lenses Steaming Up On DSLR

Discussion in 'Digital Photography' started by Smudger, Dec 28, 2005.

  1. Smudger

    Smudger Guest

    Found this on the web...

    To prevent condensation
    When taking the camera suddenly from a cold to a warm place, place it in a
    plastic bag and make the bag as airtight as possible. Leave the camera for
    approximately one hour until the camera adjusts to the temperature
    difference.
     
    Smudger, Dec 28, 2005
    #1
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  2. Smudger

    Stuart Guest

    Any tips on stopping lenses from steaming up on DSLR's? For example, you go
    from the cold outside, into a warm humid place?

    Obviously, warm the lens up first, but I wondered if there are any other
    alternatives.
     
    Stuart, Dec 28, 2005
    #2
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  3. Smudger

    Stuart Guest

    Cheers for your post 'Smudger'.

    As I expected really, but unfortunately, 1 hour is not practical in my
    situation. Damn those laws of psychic's.
     
    Stuart, Dec 28, 2005
    #3
  4. Smudger

    Ray Fischer Guest

    2 lenses.
    Keep the camera warm.o
    Warm it up quickly.

    If you're in a hurry try popping it in the oven at 100 degrees for a few
    minutes. Usual disclaimer - you try it and it's your responsibility as
    to what happens.
     
    Ray Fischer, Dec 28, 2005
    #4
  5. Smudger

    Jeremy Guest

    Important to follow that advice, because the condensation may result in
    streaking of the internal optic elements, which may render the lens
    unusable. The cost of internal cleaning may be more than would be
    justified.

    This is one of those situations where an ounce of prevention is worth a
    pound of cure.
     
    Jeremy, Dec 28, 2005
    #5
  6. Smudger

    Jim Townsend Guest

    How LONG will your camera be out in the cold and how cold will it be ?

    These factors will dictate how long it takes to warm up the camera to
    a point that it won't fog up.

    If the outside temperature is 10F and you only walk a few minutes from
    your warm car to a warm building, then the camera will warm up much faster
    than it would if you had left it outside overnight...
     
    Jim Townsend, Dec 28, 2005
    #6
  7. Smudger

    King Sardon Guest

    Obviously incorrect... heat transfer goes much faster if the temp
    difference is greater.

    But this is irrelevant. What matters is the temperature of the camera
    and the absolute humidity of the air when you unwrap it in the new
    environment. You are not likely to know either, so judgement is
    needed. If the camera surfaces cloud up, it is too cold.

    King Sardon
     
    King Sardon, Dec 28, 2005
    #7
  8. Interesting bunch of responses... most of them are actually
    correct too!

    But understanding *exactly* what is happening will help you
    judge what you can do and can't do.

    Warm air can hold more moisture than cold air, and if air (at
    *any* temperature) is cooled to the point where it becomes
    saturated with moisture, that moisture will condense out of the
    air. That can happen at 80F degrees, if the relative humidity is
    higher enough. And it can happen at -40F too.

    If the temperature is warm enough that moisture will be liquid,
    and if it is cool enough it will be ice crystals that form.
    (Interesting maybe, but we are actually only interested in the
    condensation of liquid in this case.)

    Hence if you have a camera or *any* other object outside that cools off
    to some significantly low temperature (below the dew point for
    the air inside the house) and then bring the camera inside the
    house... air close to the camera will be cooled, will become
    saturated, and will condense water that forms a mist on the
    cool object (your camera). That water will leave contaminants
    on lense surfaces and other parts, hence you want to prevent it
    from happening.

    The trick to avoid fogging lenses, as everyone says, is to put
    your camera inside a plastic bag while it is cold, bring it
    inside and don't remove the bag until the camera is warm. The
    cold air inside the bag doesn't have enough moisture (because it
    is also cold) to become saturated (the relative humidity of the
    air in the bag will go *down* as it warms up). Of course once
    the camera is warm enough it will not cause the moisture in the
    air to condense out.

    So that explains what is happening, and with that in mind the
    various tricks that can be used will make more sense.

    First, squeeze as much air *out* of the bag as you can before
    you take it inside. Air is a very good insulator, and the more
    air inside that bag, the longer it will take to warm up whatever
    is in the bag.

    You'll also find it interesting that you don't need to actually
    seal the bag. All you need is to make sure that no warm air
    goes into the bag, and since there is no pressure difference
    air would not normally move in or out... which means you want to
    make very positive that if you don't seal the bag there is never
    any pressure difference! Don't handle the bag much, because
    squeezing it might well cause air to sucked into it.

    I do use ziplock bags for lenses etc, but I commonly keep half a
    dozen or so plastic shopping bags and also a roll of "kitchen
    size" plastic trash bags available in my vehicle. I can wrap a
    whole camera bag, or just the camera, or just a lense.

    To judge the temperature of the camera, don't pick it up and
    roll it around trying to feel it. That may cause moisture to be
    sucked into the bag. Just gently use the palm of your hand, or
    maybe a finger, to press against the body of the camera to judge
    it's temperature. Once it is more than about 40 degrees in
    places with normal humidity (or maybe 90 in Houston!), the bag
    can be opened.

    It will obviously warm up faster if located in a warm place,
    such as next to a heat register or whatever. But *no way* would
    I ever put a camera or lense into an oven and put it on "warm".
    That is just too risky. Set it up higher, and find a place that
    has good air movement, which will probably help speed up the
    process.
     
    Floyd Davidson, Dec 29, 2005
    #8
  9. Smudger

    John Wilson Guest

    I used to work in Hong Kong, and in summer we kept cameras (video
    mostly) in a special 'warm room' at about 35+C - if you took cameras
    out of a room air-conned to 20C you'd get instant condensation when
    you hit outside air.

    The only solution is to keep cameras warmer than where you plan to
    shoot.
    John Wilson
    jwilsonNO*
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    www.yachtsnet.co.uk - full service online yacht
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    John Wilson, Dec 29, 2005
    #9
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