I'm working on a shoot for a client that involves models demonstrating various window coverings in front of large windows.
My thought is that we'll need to gel the windows to avoid the background getting blown out.
We'll be shooting in an actual home. Can someone tell me what type of gels I'll need and the best way to hand them on the windows without leaving any residue? Where would you buy these gels? Thanks.
Any place that sells consumbles for the TV/Film industry will have rolls of 85N (Denver is the closest to me - I use Film/Video, and there's Barbizon, CEAVCO... Nationally there's Mole.com). Get something with a lot of ND in it.
Gaffer tape is your friend. Buy the good stuff (cloth)- it truly is worth it's weight in gold.
"The Almighty tells me He can get me out of this mess. But He's pretty sure you're F%$#*D!"
You can buy gels that are neutral-density by themselves (N.D), or one that is also color-correcting daylight to tungsten to match your indoor video lighting. One such without ND is Roscosun 85 and one that's a little denser, for super-bright locations is Roscosun CTO. The name of the combo filter escapes me at the moment, but google up the Rosco site and you'll be able to find one; it looks like a dark brown to the eye, but reads correct to the camera if your white balance is set for indoor.
If you had the power and budget to use HMI, you wouldn't need window gels except for maybe some ND or scrim cloth.
I have been on gigs where we had to treat very large windows, and you have two choices: apply the gel on the outside, typically by stapling and/or gaffing it taughtly to a wooden frame which is then mounted to the outside of the window, or you can apply directly to the glass. That depends on using either electrostatic cling, or very clean glass and a water spritzer and squeegee. With the water method, surface tension is basically holding the gel to the glass, assisted by some clear scotch tape on the edges where the camera can't see. You cut the gel slightly oversize, then use a razor blade to trim it to the exact dimensions for a look that's invisible. The entire process takes a long time; be sure to budget for that. If you are careful not to crease it, you can re-use the film many times.
Frame mounting outside needs to take the wind into account: it can rattle and shake the gels and frames like a kite, making audio problems as well as a distracting look.
In your case, mounting direct to the glass is going to be optimal, since you are working right around the window itself on the shots.
One last thing to consider: what is the view out the windows you'll be working with? That may also require a treatment strategy.
Forgot to mention when applying the gels to the glass with water, squeegee, and hand towel, keep a sharp safety pin on you to pop the occasional air bubble that refuses to get massaged-out by the squeegee. Also buy a pack of single-edge razor blades: they dull fast on a job like this and it's better to throw the cheap blades away after a pass or two than to mess up a large piece of expensive gel.
Some guys swear by using a little dish soap in the water spritzer. I prefer very clean distilled water and nothing else except a little clear scotch tape along the topmost edge. Others I know of use windex for the whole operation.