include data='blog' name='all-head-content'/> Airboxlights.com and Conviction Films on Lighting for Film and Video: Eggcrates; light control devices

Tuesday, November 27, 2012

Eggcrates; light control devices

Last post, one of the cool products I was talking about was a new soft eggcrate with a convenient design improvement, but I didn't spend any time on eggcrates in general.  Everyone does know how handy grids are and how they work, right?

Easiest way to explain them is by looking at one.

Here's an image showing a soft source with an eggcrate from straight on:




You see the whole source, pretty much.  Now take a look from an angle.



You see a whole lot less of it. Ergo, if you're not straight out in front of it, a lot less light will be hitting you.












Here are a couple drawings I did to explain the concept to the Patent Office. (Finally got the paperwork!  An approved patent from the USPTO! It's been several years of work, and now I have... a piece of paper. A Very Official Piece of Paper.)




You can see in figure 7 that much of the light which scatters up and down off the surface of the front diffusion panel is blocked by the slats of the eggcrate; only those beams of light which are going roughly forward are permitted to pass.



You can buy this stuff in 24"x40" sheets if you need it for a custom light you're building like a chicken coop or something like that. If you're in New York, Canal Plastics sells it. (Off topic, but they also do CNC laser cutting of acrylic sheets!  Give them an Illustrator or other vector file, and they'll laser that out of a sheet of acrylic for you.  I made a bunch of custom stencils like that one time. Anyway.)

On Real World 10 in New York, we built piles of custom softboxes and we handmade eggcrates out of lauan for all of them!!  That was a labor of stupidity.  But, to be fair to us, that was before the internet was the INTERNET, where anyone can find anything anywhere in a matter of minutes.  It was 1999-2000.  So since we didn't know where to get the stuff, we made it.  Young and energetic and determined. And underpaid.  It was a great-looking season though. Towards the end of the build I think I just slept in one of the cast bedrooms instead og going home.  20-hour days dont lend themselves to getting much sleep.

Honeycombs work the same way, but they're much more durable than plastic eggcrates or "louvers" as they are called by most manufacturers. Honeycomb is also made of thinner material, and can be manufactured in smaller cells, making for a tighter beam control pattern.

Honeycomb is also quite expensive. Each eggcrate I bought for my old Parabeams, approximately 28"x28", was about 250$.  Pricey.

I've seen a couple very clever ultralight honeycomb style devices at some trade shows. One was made by Gekko, the LED company, as an accessory to their Kelvin Tile.  I wish I had a photo.  It was a honeycomb, but it looked like it was just an array of little 1/2" long plastic drinking straws standing on their ends held together in a frame. It was as effective as an aluminum honeycomb but was much lighter weight and ought to be cheaper.  Kino flo is making plastic honeycombs now for their new Tegra kinos. Theirs is plastic.  I wish I knew where to get sheets of lightweight plastic honeycomb that I could cut into appropriate sizes for my Airboxes.




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