Fogging lens

DJ Kast · February 1, 2011

Hey all,

I was looking around for some products that help prevent the lens from fogging up and I found this: http://www.filmtools.com/neclfogel.html

I'm curious as to whether anyone else has used this, and if it worked. Also, I'm kinda creeped out about rubbing a dry cloth made of who knows what on crazy expensive glass, so I'm hoping someone else has used this and can verify it for me or suggest something else.

Hopefully the suggestion doesn't involve an AC continuously blowing a hairdryer on the lens...been there done that!

Chris Keth · February 1, 2011

I wouldn't use any kind of anti-fog on a lens. Viewfinder maybe, but never a lens. The way to get a lens not to fog is to give it the time to acclimate to the temperature. Fog only happens when cold glass hits warm, comparatively humid air. When you move inside, get the body and lenses in ASAP, open the lens cases so they're exposed to the air. It doesn't really take all that long. By the time the scene is rehearsed and marked, they should just about be there.

Edited February 1, 2011 by Chris Keth

Tom Jensen · February 1, 2011

I wouldn't use any kind of anti-fog on a lens. Viewfinder maybe, but never a lens. The way to get a lens not to fog is to give it the time to acclimate to the temperature. Fog only happens when cold glass hits warm, comparatively humid air. When you move inside, get the body and lenses in ASAP, open the lens cases so they're exposed to the air. It doesn't really take all that long. By the time the scene is rehearsed and marked, they should just about be there.

Chris, it sounds like you have gotten a great deal of experience this winter. ;) I always kept a blow dryer in my kit and have used it on more than one occasion.

Chris Keth · February 2, 2011

Yeah, Tom. Detroit is a pretty great primer on working in winter weather.

A blow dryer can speed things up if you need it. We've found that if we bring the bodies and lenses inside first, they're warmed up by the time we do our other work like moving popups, and enough lighting is done for people to want a look at the scene. I don't think we've even pulled out the blow dryer, though we do carry one.

Chris Keth · February 2, 2011

By the way, if you're strapped for time heading inside (and when aren't you) take the lenscaps off the lenses and set them on top of the foam. They'll warm up faster. Obviously do this well out of the way of foot traffic, ladders, etc.

DJ Kast · February 2, 2011

We're always strapped for time! :)

The one instance I'm trying to avoid running into again, was we were shooting in a warm barn on a 10 degree day, and it was a run and gun stills shoot (26 shots and 5 locations in just two 10 hr. days!) so we had to run from outside to inside pretty frequently, and the steam from the cows breath expecially was killing us! Luckily the farmer had a hair dryer, so I used that on the lens while we were shooting.

I was just trying to find another way to prevent the fogging in case I ever find myself in a situation where power isn't accessible, and time is a factor again.

Chris, what foam are you referring to? Thanks for all the advice guys!

Chris Keth · February 3, 2011

We're always strapped for time! :)

The one instance I'm trying to avoid running into again, was we were shooting in a warm barn on a 10 degree day, and it was a run and gun stills shoot (26 shots and 5 locations in just two 10 hr. days!) so we had to run from outside to inside pretty frequently, and the steam from the cows breath expecially was killing us! Luckily the farmer had a hair dryer, so I used that on the lens while we were shooting.

I was just trying to find another way to prevent the fogging in case I ever find myself in a situation where power isn't accessible, and time is a factor again.

Chris, what foam are you referring to? Thanks for all the advice guys!

The foam of the lens cases.

DJ Kast · February 3, 2011

Gotcha! thanks guys.

Matt Kelly · March 26, 2011

Canned air can work to..... Just blow the fog away :)

Mitch Gross · March 27, 2011

Keep silica gel packets in the lens case to help absorb moisture. A tungsten fresnel light is the perfect way to quickly dry out a lens. Pull the lenses out of the case, pull off the caps and sit them under the lamp. They'll dry out quite quickly.

Matt Kelly · March 27, 2011

Silica gel is a great idea! That really works good?

Mitch Gross · March 28, 2011

You can buy a dessicant cartridge from PortaBrace to stick in your case. Just remember that eventually they get saturated with moisture and eventually you need to dry them out as well. I believe you stick them in the microwave or some such thing. Instructions come with them.