Egg Crates vs. Grip Solid

Brian Dzyak · October 15, 2007

When using a Chimera as a key, I prefer to use a grip solid on a C-stand to cut the spill off my backgrounds.

I'm noticing a lot of guys now attaching the eggcrates to the outside of the Chimera, claiming that it does the same thing without the extra gear.

I've tried using an eggcrate but it seems as if I'm losing up to a stop or two of light from my subject. I haven't had my meters with me when I've tried that so I can't be sure. Can anyone verify this?

Thanks!

timHealy · October 16, 2007

You would certainly lose light on large diffusion frames just as one looses light on a softlight or Kino flo while using eggcrates. But eggcrates do help control light in a way a single flag may not be able to control, especially if space is at a premium. If shooting in a stage where you may have a lot of space to get a flag or cutter were you need it, it is not an issue. I don't think you'll get standard amount of light loss as it will change with different lights and different degrees for the eggcrates. Light Controls makes a lot of eggcrates for large diffusion frames and Chimeras and they offer them in varying degrees like 30, 45 and 60. The larger the degree the more spread and the larger the eggcrate holes and vice versa. You'll certainly get more light loss with the smaller degree eggcrates than the larger.

best

Tim

Brian Dzyak · October 16, 2007

Thanks Tim!

My usual interview setup is a 650w ARRI with small or medium Chimera sitting about seven feet from the subject. And yes, usually in a relatively small room where rear walls are anywhere from fifteen feet from lens to no more than twenty-five, so keeping that spill under control is a big deal for me. I usually have no trouble having enough room to set a flag so that's not really the issue. I sometimes have to travel light and bringing extra C-stands and flags isn't always an option.

I guess the answer would be to bump the key to at least a 1K so the light loss from the eggcrate keeps me from pulling out the iris wrench. ;)

Thanks!

robert duke · October 16, 2007

the Inverse square law pops up here. in order to get that flag in there you are backing the light out. the light loss with an egg crate is relative to the distance back to accomodate a flag. I havent metered it but I hedge to guess that the light loss from an eggcrate is roughly the same as backing the light back a couple feet.

I always try to have a eggcrate on soft boxes. They make it easier to control the spill from a soft source. They dont cover what a flag can but do a great job.

If you have to travel light. bump up your lamp to a 1k and carry the eggcrate.

Brian Dzyak · October 17, 2007

the Inverse square law pops up here. in order to get that flag in there you are backing the light out. the light loss with an egg crate is relative to the distance back to accomodate a flag. I havent metered it but I hedge to guess that the light loss from an eggcrate is roughly the same as backing the light back a couple feet.
I always try to have a eggcrate on soft boxes. They make it easier to control the spill from a soft source. They dont cover what a flag can but do a great job.

If you have to travel light. bump up your lamp to a 1k and carry the eggcrate.

Thanks, Robert!

With my typical setup, I'm not forced into backing the light up any. There's always room to work the stand and solid in. For me, anyway, it's more a question of efficiency since I have to work alone. Carrying the extra hardware and taking the time to set it up isn't always feasible, especially when I'm traveling.

Sing Lo · October 17, 2007

Inverse square law doesn't apply to eggcrates...it follows some other "non-linear" law. From my experience with Chimera fabric grids, 40 degrees eggcrates has -2 stop loss, 20 degree eggcrates: -4 stops, depending on the dimensions and type of your softbox.

There is a free eggcrate calculator to work out the light loss you need in Lighttool web site. The good thing about fabric eggcrates are that they can be folded up and light weight....ideal for location. It is very quick to set up.

Sing Lo · October 17, 2007

40 degrees crates are better buy. The downside of very deep eggcrates (20 degrees) are their steep price, large light loss and the dramatic change in light quality: the light is very directional and it loses the wrap-around quality of softbox. So you get deep shadows on talent's face unless appropriate fill is applied.