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Old January 14th, 2006, 12:33 PM   #1
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Help on background lighting

Im trying to make interesting shapes ( random, vertical, horizontal, window shapes, etc) appear in light behind subject on the background wall surface. I have black 20x30 foamboard, assorted worklights and different lamps to screw into them. I cant seem to make a clean light pattern on the wall with the shapes that I cut out. Can someone tell me what type of "guerilla" lights to use, size that cut outs should be on 20x30 foamboard to make decent believabel window shapes, angles, and also the distances (ie; how far back the pattern is away from the background wall to be lit, and how far the light source should be away from the pattern) I'm stuck!!!!!! so far I have tried a halogen spot/flood par20 50w in a aluminum clamp light and the spill from that worked better that the actual beam did. Have also tried assorted household lights. Tried all at different distances and angles and still frustration.
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Old January 14th, 2006, 01:03 PM   #2
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If I'm reading this right you probably need a light source that is more focused. All the light sources you mentioned are very broad and soft. Think about a typical flashlight - narrow, focused beam. If you put a pencil up in front of it you'll see a distinct shadow. Now, a bank of 4' flourescent bulbs such as in an office. You'd have to get your cutout shape within a few inches of the surface to cast a clean shadow.

Typically this sort of work is done with a focusing instrument such as an ellipsoidal also known as a leko, which will give you very sharp shadows. You've really got to be careful with the mask materials you're using, though - easy to start a fire, you really don't want a flammable mask.

I don't know of a "guerilla" solution, you just need a light that focuses tightly... lekos are very inexpensive to rent from theater supply/rental houses. Ask them about stock gobos as well (little metal masks that drop into a slot in the light). And don't be using foam board, buy some blackwrap (black aluminum foil that's about 10 times thicker than what we get for our kitchens) or figure something else out that is metal and not going to catch fire.

Ask also about the width of the leko's beam for your available distance - these lights are available in different beam widths. You'll also need something more than the typical light stand to support one, I'm guessing about 14lbs.

You'll also need to fool with intensity - this thing might be pretty bright compared to your other lighting.

Oh, I've got it - try a slide projector!
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Old January 14th, 2006, 01:31 PM   #3
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Quote:
Originally Posted by Seth Bloombaum
And don't be using foam board, buy some blackwrap (black aluminum foil that's about 10 times thicker than what we get for our kitchens) or figure something else out that is metal and not going to catch fire.

Rosco "Cinefoil" brand is great for this........
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Old January 14th, 2006, 02:04 PM   #4
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As Seth mentioned, you have to start with a instrument that will allow for a sharp focus before any cookie/gobo will produce the kind of results you're looking for. Once you have that, you may need a second stand to hold the cookie at the right distance from the instrument. Experiment with distances for different effects.

Cinefoil works well. If you want precut patterns, check these out:

http://www.cooltvtools.com/cookie.html

A previous thread has already debate the pros and cons of these, may want to take a look.
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Old January 14th, 2006, 02:43 PM   #5
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would something like this work?? I wonder if they make these cheaper ones where you can just make your own custom slides.
http://www.pasternackstruevalue.com/hoimpr.html
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Old January 14th, 2006, 05:23 PM   #6
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Maybe the Holiday Image Projector (link above) would work. Hard to know until you try it. Seems like it's designed to throw an image, but they don't give you much info. Maybe you have a local hardware store with leftover Christmas stock that you could try out and return if it's not working right.

But for that price you might have a week of Leko rental, depending. (Could be $12/day, with 3 or 4 days gets you a week).

Or be able to buy a used slide projector with that money.

I didn't mention - blackwrap can be cut with scissors. Or try tinsnips on a tuna can lid, or similar weight tinplate steel. A slide projector tends to run cooler, so, if you're a foot or more away from the light you could use foamcore or corrugated. Of course the reason a projector runs cooler is that it has a fan, which might be too much noise for your application.
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Old January 14th, 2006, 07:22 PM   #7
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I bought a cheap lighting system from Ikea - they call it "isbrytare" (where do they get those crazy names from?) it has a focusing lens and comes with 4 different coloured glass filters, plus various cutout metal stencils (Would you call them Gobo's?). Its cheap and very useful, although there is a bit of spill light you have to block out. Have a look on the Ikea site and there may be more details (I bought this product in England but I'm assuming they stock it everywhere...)
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Old January 15th, 2006, 04:23 AM   #8
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Nice one Paul!

http://www.ikea.com/webapp/wcs/store...ts=10111*10448


. .and I also saw this .. great minds . huh?

http://www.blue-room.org.uk/index.ph...&mode=threaded


Grazie
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Old January 15th, 2006, 07:46 AM   #9
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Paul - I bought the IKEA lamp a couple of years ago - it's phenomenal!
I only paid 25 for it as well.
I've used it quite recently on some interviews, just to throw an interesting pattern onto the background ( I used the "window "frame gobo) and it really looked good. I've shown it to a few of my lighting colleagues, who really think it's great value for the price - especially as the Dedo version would cost more like 1000...

Robin
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Old January 15th, 2006, 10:50 AM   #10
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Great Find!! I just wonder, since it is electric and sold in UK what the differences are on plugging it in over here in the states. Anybody know. Maybe just an adaptor or something.....if that. I want one!!
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Old January 15th, 2006, 12:07 PM   #11
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Quote:
Originally Posted by Steve Witt
Great Find!! I just wonder, since it is electric and sold in UK what the differences are on plugging it in over here in the states. Anybody know. Maybe just an adaptor or something.....if that. I want one!!
Also available in the US Ikea site as a 120v:
http://www.ikea.com/webapp/wcs/store...roductId=33653

$40 USD - this really does look great.
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Old January 20th, 2006, 07:14 PM   #12
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use a highpowered flashlight

cheap solution
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Old January 20th, 2006, 08:03 PM   #13
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Well, Im not sure how powerful it would have to be. I'm gonna invest in one of those Christmas projector lights (notice that I did NOT say "holiday" light) that shoot a focusable beam of powerful light for a pretty good distance. I've always wanted one of those things anyway. They can be used for lots special events (birthday, aniversary, valentines day,) come with lots of slides. I will make my own cookie or gobo, whatever you want to call it for whatever pattern I want and focus the beam thru the pattern and onto the wall for a clean sharp light pattern. See the link below!!
http://www.pasternackstruevalue.com/hoimpr.html
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Old January 23rd, 2006, 07:45 PM   #14
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Quote:
Originally Posted by Seth Bloombaum
Also available in the US Ikea site as a 120v:
http://www.ikea.com/webapp/wcs/store...roductId=33653

$40 USD - this really does look great.
Yeah - I bought one a few months ago. I thought I was being so sneaky! I easily adapted a baby stud onto it so I could toss it on a C-Stand... very neat for the money. You can get cheap china balls there too.
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Old January 24th, 2006, 10:22 AM   #15
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Steve, the problem with having a lighting instrument that is not focusable is that you have to get the gobo at exactly the right distance from the lamp in order to focus it. Even lights with some sort of parabolic reflector behind them are inherently pre set to one specific focus. It's just that that focus point is usually designed to produce an even, useful light rather than for projecting an image. Even if you do find the focal point to project an image, your gobo may not be the right size to project the size of image you may want, or there may be either not a wide enough beam to cover the gobo, or spill around the edges you need to flag off. Also, depending on the shot, you may want to defocus the image slightly, which means adjusting again. It's no wonder you're frustrated.

At a minimum, something like the Lowel Pro light can offer enough focusing ablity to project a reasonably sharp pattern through a larger gobo. Remember, you want the smallest focusing light possible, with the widest ability to flood for sharp images. It can be had for around $200:

http://www.bhphotovideo.com/bnh/cont...goryNavigation

Also, I happen to be rather fond of the Lightbreak kits. They are not exactly cheap, but a set runs about $150 for 4 patterns screen printed onto heat-resistant mylar.

They also include a nifty how-to on using the pattern. Ideally, for the sharpest pattern, you want a very small light at full flood, a very large pattern/gobo placed as far as possible from the light, and place the gobo as close as possible to the subject:

http://www.lightbreak.com/howto.php

I understand that all this is probably out of your price range, but maybe this will give you additional ideas. Hope it helps.
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