Darkness Posted January 19, 2011 Share Posted January 19, 2011 I recently purchased some LED par 64 laterns to create some colour washes, mainly from behind/side stage. I thought I'd try hanging some infront of the stage so I could add some colour from the front and they work fine but the spill is a bit too much, I could live with it but would be nice if I could narrow the beam down a bit. I thought some barn doors might do the trick as they work well on fresnels to stop the same problem. I contacted a company about sizes of barn doors and they said barn doors don't work on LED par cans, I can see the reason why this may be true due to the multiple LEDs as apposed to a halogen lights single lamp but was just wondering if it is true that barn doors don't work on LED pars. Link to comment Share on other sites More sharing options...
Ashley R Posted January 20, 2011 Share Posted January 20, 2011 You really must want one tight beam, unless you have a nice LED par that happens to have a wide beam angle. But then again the amount of ambient spill from LED cans is a bit much. I haven't actually tried proper barn doors that you find on Fresnel's, But I have tried Cardboard and gaffa :** laughs out loud **: Worked all right, and I might suggest that you also just give it a try, to see if it produces the desired effect before you buy proper ones. Link to comment Share on other sites More sharing options...
Neil Hampson Posted January 20, 2011 Share Posted January 20, 2011 Barn doors do work reasonably well on a standard Parcan, and I see no reason that they wouldn't work on an LED one, however for a 'tighter' overall beam barndoors may not be the answer, I would say a 'Top Hat' with spill rings would work much better to get the effect that you want, barn doors are more for just cutting one or two edges off, such as the edge of the stage, or up the edge of the Pros' arch, even with a fresnel, you need to close the doors in a long way before you are tightly controlling the beam. Link to comment Share on other sites More sharing options...
Brian Posted January 20, 2011 Share Posted January 20, 2011 They do work; just not quite as well. If your fixtures use separate R, G and B leds you'll get a bit of colour fringing. Whichever type of can you use the edge isn't as good as on a conventional source. The light out of the front is not a solid cone - put a bit of card up close and you'll see splodges of light. This means the barn doors affect the leds at the edges more than those in the middle giving a less smooth edge. Whether it matters in your application only you will know. Try Ashley's idea of cardboard and gaffa tape. Link to comment Share on other sites More sharing options...
Darkness Posted January 20, 2011 Author Share Posted January 20, 2011 It's not a tighter beam I'm after its just reducing the light that is spilling onto the pros arch and floor infront of the stage. I'll give the card board idea a go. Link to comment Share on other sites More sharing options...
swampman Posted January 20, 2011 Share Posted January 20, 2011 Try locating some "eggcrate": it is made of alumimium strips cut about 1cm wide and placed aligned on two axis to make squares perpendicular to the light beam: I salvaged mine from old fluoresent false ceiling lights where it is used to control glare and sideways spill. Hopefully the grid will coincide randomely with the RGB matrix and not cause uneven coloration. Easily painted black with a spray can and cut to size with side small sharp cutters but the fun comes designing something to hold it in front of the lightsource and securing the edges from falling apart... Worked well on 500w floods to cut camera/performer blinding and uncontrolled beams at a local TV studio built on near zero budget. Link to comment Share on other sites More sharing options...
Just Some Bloke Posted January 21, 2011 Share Posted January 21, 2011 I have tried Cardboard and gaffa :** laughs out loud **: Worked all right. Just a warning to anyone reading this who hasn't picked up on the fact that these are LED Pars. Don't try this on standard PAR 64s using CP lamps as the heat produced by the lamp could easily burn the cardboard and you could have a nice fire on your hands! :D Link to comment Share on other sites More sharing options...
Ashley R Posted January 21, 2011 Share Posted January 21, 2011 I have tried Cardboard and gaffa :** laughs out loud **: Worked all right. Just a warning to anyone reading this who hasn't picked up on the fact that these are LED Pars. Don't try this on standard PAR 64s using CP lamps as the heat produced by the lamp could easily burn the cardboard and you could have a nice fire on your hands! :D And is the only reason why it works! LED, the only reason why alot of my weriod builds dont burn! The regular Par can equivalent could be a sheet of aluminum and bulldog clips? or a bit of sheet metal, drill and rivets for a more permanent option? Link to comment Share on other sites More sharing options...
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