Light Spill from Strand SL

fredthe

Active Member
Joined
Dec 13, 2006
Location
Maryland
So, the newly renovated theater at a local HS where I help out has bunch of nice, new Strand SL 19-degree for the FOH loghting position...

The problem we're having is that there is a sloped ceiling above the lighting position, that is parallel to the beam of the fixture (when focused on stage) and about 5 feet above the beam. There is a LOT of "spill" from the front of the instrument, which is doing a good job of lighting up the ceiling. It's almost as if light is being reflected sideways from the inside of the barrel.

Has anyone else seen this behavior? Is this something unique to the SLs? Or, is this a ususal problem with Ellipsoidal fixtures, and I just hadn't noticed before?

-Fred
 

pyrus

Member
Joined
Apr 12, 2007
Location
Colorado Springs
I can't say for sure about Strand instruments, but you are going to get that sort of thing with any instrument. The best solution I can think of is to put a top-hat (snoot, whatever you refer to them as) on it to cut that down a bit.

the problem has a large part to do with the lenses not directing the entire beam in one direction, they refract some of it off in odd directions.
 
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wolf825

Senior Team Emeritus
Premium Member
Joined
Apr 7, 2003
Location
Eastcoast USA
Have not heard of this problem with the SL's... Is this one or two fixtures or all of them? Have you determined if this is coming from the front of the fixture--or is it leaking thru the shutters/gobo slot? It almost sounds like the lense or lense tube is out of alignment and refraction is the result..... Very odd..


-w
 

fredthe

Active Member
Joined
Dec 13, 2006
Location
Maryland
It's the same on all of them... and it is out of the front of the instrument... you can see light on the ceiling change when putting a scroller on it; the same as if it had a short top-hat.

I was in another theater this evening, and their lekos (couldn't get close enough to see which brand) were doing something similar, but they had a black ceiling, so it wasn't as noticible.

I guess the real problem is the light gold color of the ceiling. The architect probably never thought of light spill. (Among other things; don't get me started on the always-on emergency flourescent light in the catwalk...)

Time to make some one-door barn doors :)
 

stantonsound

Active Member
Joined
Feb 18, 2005
Location
Charlotte
We usually put gel extenders on these fixtures to cut this down. It is pretty much a short top hat with a gel frame on the end of it. This seems to fix the problem. You are not the only person to notice this.

For gobos, use a donut to make the images sharper and keep this from happening. I think the new SL's have a few great features (I like being able to rotate the fixture in the yolk hanging harness), but I still like the Source Four's hands down.

Their color and throws are much more consistent and usable in the real world.
 

SAWYeR

Active Member
Joined
Feb 17, 2007
Location
Chicago, Illinois
Top hats and Apollo Blackwrap (matte black tinfoil). Put on the tophat, and a bit of blackwrap on the top 1/4 of the top hat. Usually works for me. Then again, making a full tophat out of blackwrap (always interesting) can help. And always on flourescents? I know the feeling.
 

Balo

Member
Joined
Apr 24, 2007
Location
Based in Portland, OR - Touring
Hi There,

I have 20 of them in my FOH, and they don't create anymore spill than any other fixtures I've used in a near ceiling FOH position. Like everyone else has mentioned, try a top hat, a half hat, or a gel extender. You also might want to try bench focusing them, they're close out of the box, but all lekos need some bench TLC every now and then.
 

Kelite

Well-Known Member
Premium Member
Joined
Sep 23, 2005
Location
Fort Wayne IN, USA

squigish

Member
Joined
Dec 27, 2004
Other things that can affect spill:

Shuttering--if your shutters are pushed in a decent amount, there's going to be some light that bounces off of them and back into the reflector, and then comes back out at a less-than-ideal angle, which the lens(es) can't focus properly. This is really only a problem if your shutters are pushed in a lot, which is not that likely for a frontlight system, although I don't really know what you're using it for.

Frost--this is sort of a 'duh' kind of thing, but putting frost in your frontlights adds dramatically to your spill. Also, if you do use color extenders, and put frost at the end of them, you're basically rendering the color extender useless as a top hat, because the light is now coming from the frost.

And what everbody else said, too.