How to recreate a window with condensation?

[Urban Skargren]

Hello! I am going to shoot a short film, and in a scene a person paints on a condensated window with her finger (in order to look out). The scene will be shot in a hot/tempered climate but we want to imitate the effect as if the day outside were cold.
How can we believably recreate condensation inside of a normal window - and without the camera being condensated?
The solutions that came to my mind were:

a) Somehow cooling down the glass
b) Cook water in the room and let the steam fill the air (but the glass of the lens would also be condensated)
c) Use some kind of spray

Does anybody have a solution to this?

[Battle Vaughan]

Don't know what US products are available to you there, but I've used Krylon Dulling Spray to mimic condensation on glassware in food shots (http://www.krylon.com/products/dulling-spray/)/. Once years ago I used, if I recall correctly, camphor dissolved in alcohol to brush on a "frosted" appearance to a glass window in a food set. It does evaporate over a few hours, so has to be fairly fresh.

[Oren Arieli]

Rent/borrow a clothes steamer. I'm pretty sure it will work unless the window is in direct sunlight and quite warm. You can also try spraying with a water/glycerine solution.

[John Mahoney]

Borrow the iron your wife uses on your shirts.

[Urban Skargren]

Thank you, I did many tests with many different methods (glycerine, vaseline, deodorants, powder, water spray, soap spray, flower-water spray, vaporizer...) Unfortunately I don't have access to "dulling spray", I think that possibly would have been the best! Of all the techniques, I found that the most realistic is to cool down the window pane in a fridge (we will use a attachable glass pane and it's a rather small window), that creates a nice condensation (only thing it creates condensation on both sides, I need to wipe the back side clean to be able to "paint a hole" in the condensation).

I also discovered that if I use a vaporizer on top of that cooled condensation, it can possibly create even more tiny water drops on top.
But I also discovered that the condensation depends a lot on the surface of the glass. If I cleaned the glass with soap and let some soap stay on (then cooled it down), almost no condensation built up on it. If I cleaned the glass with dry kitchen paper, it left more condensation. If I smudged a kitchen paper with vaseline and smeared it on, then wiped it dry, leaving a thin layer of fat, it created a really nice "frozen surface" that stayed for long (like in car windows, I recall) The surface should also be completely dry before cooling it down... So there is my movie condensation investigation, we're shooting next week.
Hoping one day to have a special effects-department doing these crazy things for me

[Urban Skargren]

Ok so now we have shot the film, my solution was to use a fridgerator on the set. We were in the country-side, in a house that had no furniture what so ever, so it wasn't the first solution I thought about, but we made the effort to transport a whole fridge on a pick-up to the location, put it on maximum cold and had 4-5 different tailor-made window panes constantly beeing cooled down, and just took out one at a time from the fridge, while putting in another to be cooled down, thus we could easily swap panes as soon as one warmed up and lost its condensation. The window was small enough so that they fit in the fridge. And in this case we needed to wipe the panes dry on the back side first before putting them in front of the camera so that the glass would be pretty clear to look through once the actor "painted" with her finger on the glass. We also used a broad light from behind the camera to make the condensation "shine" more.

It worked like a charm, and knowing that the glass needed to be just a little dusty to easily create new condensation was key. We hade a vaporizer to fill in some wholes in the condensation, that also worked. But only using the vaporizer, the "condensation" would be too thin and fade away too fast.