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Old June 15th, 2006, 11:23 PM   #1
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Metal honeycomb or grids?

I'm putting together fixtures modified slightly for compact fluorescents and I want to use grids. I got plastic grids and painted them flat black, but the plastic grid is a bit thick and I estimate I lose about %20 of the direct light. Obviously, I want to cut out the indirect, off-axis light, but I don't want fat grids stealing lumens from the subject. I can live with things as they are, but I would rather have fine metal honeycomb or square metal grid. I would like at least 1/2" deep but no more than 1" so they will fit behind the barn doors. The big criteria is the overall size. I am using 12" reflectors so the typical 7" honeycomb will not suffice. I need at least two, but I have three lights so a 2'x2' sheet would be perfect. Any ideas?

Last edited by Marcus Marchesseault; June 16th, 2006 at 02:23 AM.
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Old June 16th, 2006, 04:57 AM   #2
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Hi Marcus...

My softbox uses a fabric grid that's about two inches thick. Made entirely of what looks like cordura nylon and held in place with velcro. This is a softbox that's used in conjunction with a 1000-watt Lowel Tota Light.

With a fluorescent light source you could probably do the same since there's not much heat to contend with.

Several years ago a friend from Boeing gave me several sheets of metal honeycomb but I never did use it. So I donated it to Honolulu Community College's aviation school. Norman strobes use that particular material for their honeycomb grids. It provides a very tight light pattern but there is some light loss, too.
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Old June 16th, 2006, 07:14 AM   #3
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Thanks for the idea, Dean. I suppose I could cannibalize a fabric grid since I'm not generating much heat. I like the idea of velcro to speed things up. I guess a few longer grid cells is more efficient than hundreds of small cells. Also, the fabric in the grids is not as fat as the plastic. It will be hard making the first cut on that fabric, though!
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Old June 17th, 2006, 04:26 PM   #4
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Marcus....

I used to buy ripstop nylon from a place called High Performance Kites. I don't think they're around anymore but most kite places might have similar material. The kite shop, by the way, didn't disappear because it did poorly. It did very well. And when the owner exported yo-yo's to Japan he made millions.

The owner sort of retired from it and went onto other things. And I don't think he's even 50 yet.

Maybe we're in the wrong line of work?

Stitching the grid together might be a little tricky. If you want to take a look at the grid used with the Chimera softbox let me know.
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Old June 17th, 2006, 06:44 PM   #5
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I actually have a fabric grid from a chimera knock-off that I can use. The difficulty will be getting the courage to cut apart a perfectly good grid! :) It really wasn't that expensive, so I won't feel too bad.
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Old April 6th, 2007, 09:03 PM   #6
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Metal honeycomb grids

I have some 24" x 24" aluminum honeycomb grid material in a .625 thickness in sizes ranging from 1/8, 3/16 and 1/4" cell sizes. You will lose some light regardless of what you use but the honeycomb shapes light in a more accurate and controllable manner than floppy fabric grids.

I can run some tests to see how much light is lost if you are interested. More light is lost in the areas where you don't want it.
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Old April 7th, 2007, 06:08 PM   #7
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Larry, I can't see the harm in running some tests. Those cell sizes sound awfully small. Maybe just test the 1/4"? Is that a structural material that you have adopted for use in lighting?
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Old April 8th, 2007, 04:56 AM   #8
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Quote:
Originally Posted by Larry Vaughn View Post
I have some 24" x 24" aluminum honeycomb grid material in a .625 thickness in sizes ranging from 1/8, 3/16 and 1/4" cell sizes. You will lose some light regardless of what you use but the honeycomb shapes light in a more accurate and controllable manner than floppy fabric grids.

I can run some tests to see how much light is lost if you are interested. More light is lost in the areas where you don't want it.
Where did you get it? What color is it, just natural silver? Do you paint them black? I think Marcus wants a larger aperture too.
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Old April 8th, 2007, 04:59 AM   #9
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I wonder how hard it would be to make a honeycomb grid in fabric--larger aperture size. You never see honeycomb in fabric, only metal from what i've seen. Also, I never see large aperture in honeycomb--must be hard to make. Maybe the square ones are best for you since you want the larger cell size.
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Old April 9th, 2007, 07:07 PM   #10
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grids

Marcus, what model/brand light units are you using?

I have some 12" x 12" grids in 1/2" thickness and 24" x 24" square grids in a .675 thickness at 1/8", 3/16", and 1/4". I can get any thickness, cell size and metal density up to about 1/2" cell size and approximately 4' by 8' sheets or bigger if necessary. Some of the cell material is strong enough to walk on, but they all need a frame around the material for support and to keep the material from flexing.

Lightboxes might need an adjustable strut that extends from the bottom horizontal end to the light stand so things don't sag and jiggle. The stand should be strong and heavy enough to support everything. The super light ones are a bit too flimsy and personal experience shows that those type stands aren't worth the money they cost. Your lights might end up on the floor broken.

That's where the fabric grids have a weight and cost advantage. I'm sure someone in China or Korea is getting 15 cents an hour to make them. But if you use them outside in a windy area, weight is needed to keep things from blowing down.

I have an old Chimera that is about 4' by 6' and it sags by itself when attached to a While Lightning Ultra light.

My tests show that they should be coated with heat resistant flat black paint. Uncoated grids reflect the light a bit more, which might be ok in some applications. Raw grid material comes in various surfaces including raw aluminum, anodized and others.

This material is used in many applications such as fluid redirection and impact energy dissipation for example. Large blocks of the material can be cut on the bias for directional control. Don't walk signs have a larger grid over them so diagonal pedestrians can't see them. The cell size looks like about 3/4" or bigger. A local Walgreens drug store has grids over the lights in the parking lot so they only illuminate the building.

My idea, with input from lighting guru Nino G. (not related to Kenny G.) is to make some framed grid units that can be used with any hot light to channel the light into a controllable beam. The grids could be mounted on a separate stand by themselves or with some type of extension arm to fit a c-stand for example. I was talking to Matthews today about this. Might as well go with the best because in the long run it will end up being more dependable, durable, safer and more professional.

Actually in preliminary handheld and softbox tests they work very well and the lighter sizes also work with the smaller sized Photoflex Silverdomes, for example, without any additional support they fit inside the velcro face of the domes. I bought the three smallest sizes so plan to make grids to fit all of them to duplicate lighting effects on www.englighting.com

With grids one I think one can take an open faced light and get the directional control of a fresnel spot with lighter weight and cost overall. The smaller grid sizes make a nice small spot effect.

I should have a couple to fit my small silverdome within a week or so, about 24" x 31.5", which is about the actual inner face dimension.

I'm interested in requests and input from people who are looking for such products, because it is my intention to create some custom units for testing and subsequent manufacturing.

I am also going to make some grids to fit 4' fluorescent units.

Check the www.tomgreen.com website for potential applications. He has several hanging from his living room ceilings. I might do the same with my own units.

I should mention the the larger grid sizes have less metal in them per surface area, so they weigh less and block less light as compared to the smaller sizes.

As far as cloth grids go, make a trip to the local fabric store and chat up one of the nice ladies behind the counter and see if they know anyone who might make one up for you.

Just for fun you could take some cardboard grids out of a liquor box and mess around with them to see what the effect is using larger grid sizes. Just don't use any bulb that products much heat or you will have flames to contend with.

Last edited by Larry Vaughn; April 9th, 2007 at 07:54 PM.
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