Shooting in the cold

Eugene Lehnert · October 3, 2005

I want to shoot timelapse stars at night using my Bolex. How can I prevent condensation from building on my lens due to the low temperatures at night this time of year? Do I need a heater?

Annie Wengenroth · October 4, 2005

I haven't tried this myself but you could throw one of those "space blankets" (you know, they look like they are made of foil) over the camera and that may help keep things at a constant [warmer] temperature.

Dimitrios Koukas · October 4, 2005

I want to shoot timelapse stars at night using my Bolex. How can I prevent condensation from building on my lens due to the low temperatures at night this time of year? Do I need a heater?

Are we talkin about a cold winter night with no clouds?

Dimitrios Koukas

Dickson Sorensen · October 4, 2005

Bolex used to offer a service to winterize their cameras. Basicly they replaced the greese in the movement with thinner oil. Years ago I had a Bolex and shot a lot of material in the mountains in Colorado much of it time lapse. I didn't have my camera winterized and never had a problem. this was at temperatures above 0 deg f. Condensation on the lens is another problem. If there is warm moist air from inside trapped between the lens elements and you take the lens outside thereby cooling the glass you can get condensation. When you bring the camera back inside you will get more but generally then it is on the outside elements.

Keep the camera cool for many hours before using it outside. If you get some condensation shine a bright light (like 1000 watts)into the lens and often you can get rid of the condensation. Do this outside where the air is dryer. I worked on a film in Canada and we kept our lenses in the truck all night long to avoid having problems in the morning. Batteries are the opposite keep them warm always.

Eugene Lehnert · October 5, 2005

I took my camera out the other night and I didn't have any problems with condensation until late in the night. The temperature dropped below 50 degrees after midnight and I would clean the lens off but it would then fog over shortly after. I was on a lake shooting timelapse stars. The sky was clear without a single cloud.

Do I not have to keep my lens warm to prevent this?

Dickson Sorensen · October 5, 2005

I took my camera out the other night and I didn't have any problems with condensation until late in the night. The temperature dropped below 50 degrees after midnight and I would clean the lens off but it would then fog over shortly after. I was on a lake shooting timelapse stars. The sky was clear without a single cloud.

Do I not have to keep my lens warm to prevent this?

As I understand it here are the physics: Air contains moisture, warm air contains more moisture than cool air, as the air cools it will reach the dewpoint. The dewpoint is the temperature at which the air is saturated with water and can not hold any more. If the temperature lowers any further the water will be condense onto the nearest surface. In your case it was your lens. It was also collecting on any surfaces, the legs of your tripod, rocks nearby etc. If you can keep your lens surface temperature above the dew point water will not condense on it. Near a lake you can be sure the humidity was high therefore a higher dew point. If you warm your lens once it is outside this will help though don't do it with anything that puts more moisture into the air as example a propane heater which is producing more moisture as it burns. Use an electric sorce if possible. There are products which are applied to a lens to reduce fogging. I do not reccomend putting them on a camera lens as the may be harmfull to the coatings and difficult to clean off. I have used them however on the eyepiece as an extreme measure and found that they can be helpful.

Charles MacDonald · October 8, 2005

There are products which are applied to a lens to reduce fogging. I do not reccomend putting them on a camera lens as the may be harmfull to the coatings and difficult to clean off. I have used them however on the eyepiece as an extreme measure and found that they can be helpful.

AS a former Scuba diver, we would have the reverse problem, cold water on the OUTSide of the mask, which caused condensation on the inside. To clear you would have to flood your mask, which is no fun in Northern (2 degree c) waters..

If you were to put a filter on the lens, and seal it tight, (ie tape) the Condesation would be oon the outside of the filter. You Could put some prodcut on the (disposible if needed) filter. Dacor sold some stuff that was basically a soap. You would wet the surface, and the condensation would just join the liquid there, the other one I found worthwhile was a waxy stuff.

If you cange film in the cold, of course you will have mosit air INSIDE the camera, which may fog the BACK of the lens.