Posted 20 February 2006 - 04:50 PM
I had used some straw on one that worked ok by placing it on the barn doors with the usual clothes hangers. This kept it away from the lens a few inches at least, depending on the door position. I placed a 3/4 CTB in the same way and it started melting/warping within 30 sec. These are Lee gels made for lights.
What's the best way to do this? Do I need a heat sheild (clear gel placed behind the color)? Or am I using the wrong type of gel or what?
Posted 20 February 2006 - 05:07 PM
Posted 20 February 2006 - 07:24 PM
Posted 20 February 2006 - 08:48 PM
Generally speaking one can use Rosco or Lee inside the doors from 5k down on down. But with 5k's and 2k's you want to let it billow out so some ventilation gets in there. Outside the doors is no problem with these lights too but I prefer to go inside the doors when I can. You wind up using less gel and there is less chance of white light spill.
On 10k's and up, most large HMI's, gel on a frame works better than on the doors. On open face lights like one and 2k blondes and redheads, on the outside of the doors or a frame. On pars of all sizes keeping the gel on a frame as far away from the light the better it will last. Heat shield will also help but don't let layers of gel touch. Separately they will last for quite some time, but if they touch under use they will melt each other. Rosco sells a super heat shield that comes in sheets but the right side of the material must face the light source. You can tell the right side by using a continuity meter.
Posted 20 February 2006 - 09:43 PM
That said, an open faced light generates five times the heat (at the hot spots) of a fresnel, and you will have burn-thru. There are no gels that can surpass the heat of a bare tungsten bulb, so the rule of thumb is: the farther from the source (bulb) the better. If you must use a color very close to an open bulb, it is best to use a glass filter. Otherwise, back it off at least until it fills the barn doors.
Posted 06 March 2006 - 04:46 PM