preventing early morning filter fogging?
JimKarczewski
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Shooting at Bryce Canyon a couple days ago, it was a cold morning. My Cokin Z (Resin) filters were getting condensation. Any idea how to rid this? If I could had kept them out all night in the cold to start, I'm sure it would had helped, but wasn't an option.
Jim Karczewski - http://www.jimkarczewski.com
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Plastic/resin filters have little thermal mass and they cool quickly. Glass filters will hold their temperature longer so, if this is a continuing problem, I recommend glass filters for this application and the circumstance of condensation in high humidity.
To warm the filters I suggest a small ice chest or cooler with a couple of charcoal-type hand warmers in there as well. Keep the filters in clean plastic baggies (not necessarily food grade but optical grade) in the "warmer" when they are not in use.
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When going from a heated environment to a colder one:
- Spinning in circles holding the lens facing into the direction of the spin. Just don't let go, and don't hit anything obviously.
- keep your gear in a protected way of some sort either in the trunk of the car or bed of the truck away from the heater. Like Ziggy53 said a cooler is a good option in an SUV. One benefit of shooting while riding a motorcycle is fogging is never a problem unless you change altitudes very quickly.
- Hold the lens toward the sun. I wouldn't do it directly just incase the bright rays might damage something. And I guess this option is out if your shooting right before sunrise.
When going from cold to hot:
As Ziggy53 said, the heated handwarmer in the cooler is probably the best bet. You can get a box of handwarmers for a lot cheaper than individually.
Hope this helps.
There seems to be less and less garden in this state.
And problem with Hand Warmers.. Altitude. Higher elevations, I was told hand warmers are useless because the lower oxygen saturation has a direct effect on how they work....
Those leave a coating. While you don't notice it on a windshield, I would not recommend it on photographic equipment and I would question whether the coating itself or the propellant/solvent is safe for resin filters.
If you want to try it, use it on something you can do without.
I've used both catalytic lighter fluid warmers and the old hand warmer sticks above 14,000 feet. While they may not produce as much heat as down "below", they were still helpful (for body parts.) I have not tested the newer iron power, water, salt, activated charcoal, vermiculite packs, but I found a couple that comment about those hand warmers used at nearly 7,000 meters (over 22,000 feet) and they claim they are still effective. Their quote:
"Chemical Heat Packs: We used the same thing you'll find in REI or any hardware/hunting store: air activated (iron). Work great. Big mittens/boots insulate, but if your hand or foot is already cold, insulation has no effect, so don't even think of comparing these. Heat packs ADD warmth, which the most massive insulation cannot do. As someone noted, the higher you go, the less oxygen, so the less heat, but that's almost better; they are normally too hot, and the low O2 means they last longer."
From:
http://www.backpackinglight.com/cgi-bin/backpackinglight/aconcagua_photo_essay_gear_list.html
Look in the comments section under the article.
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http://www.amazon.com/Nikon-8073-Fog-Eliminator-Pack/dp/B0007M6GJ0
which I'm guessing is the same concept as these:
http://www.cameratown.com/news/news.cfm?id=9016
Non-liquid/Cloth based (some kind of activator has to be in there to prevent it, but.. supposedly for photo equipment..)
I'd love to buy glass filters, but replacing my resin versions is quite the cost... but something I'm sure I'll eventually do, due to the easy scratching of resin as well..
I suspect this is liquid silicone impregnated cloth, that is also considered a "dry" compound. While it cannot absolutely prevent condensation, it can greatly reduce the problem. In extremely thin coatings I do believe that it is fairly transparent, but I believe that it turns a bit cloudy at very cold temperatures.
In order to create the thinnest possible and most even coating it's probably important to use one cloth for applying a very thin coating and then a clean microfiber cloth to buff and polish the surface. You want as even a distribution as possible and if you see any coating it is too much.
I don't know if silicone is safe for plastics and resins, so my previous caveat applies, only use this on surfaces you consider expendable until you prove it safe to your own standards.
I would not use this stuff on anything photographic that I own. I believe that it is intended for "sports" optics which do not have to be optically perfect.
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