Tightening the Light

Foxinabox10

Active Member
Joined
May 1, 2004
Location
Boston, MA
I have a lot of 40 degree Altman Shakespeares and 36 degree Source Fours. The problem is that from our catwalks they are somewhat too large for what we want. My director wants round lights instead of squares, so I can't really use the shutters. Is there another way to easily and cheaply tighten the light to keep the circle. Would a snoot work?
 

Foxinabox10

Active Member
Joined
May 1, 2004
Location
Boston, MA
For the gobos, do you mean an aperature?
 

Foxinabox10

Active Member
Joined
May 1, 2004
Location
Boston, MA
How can I tell which one to get? Is there a chart anywhere for width of light vs. length w/ a certain degree with aperature?
 

Foxinabox10

Active Member
Joined
May 1, 2004
Location
Boston, MA
But I need to know how much each one will shrink it to figure out which one to buy.
 

hollinj

Member
Joined
Aug 25, 2004
Location
Indiana
I'm not a big altman shakesphere fan, but I know that the 36* S4 is the eqivelant to an altman 6x9. This fixture is primary used for top light and front from an electric not a cat walk, depending on the height of the cat you might want to switch lenses to a 26* (6x12) 19* (6x16) that will tighten your beam and make it stay round. Other wise use a appature or a doughnut (looks like a gel frame but has a smaller circle in the center. Jake
 

koncept

Active Member
Joined
Mar 6, 2005
Location
.
i would agree with hollinj. i have seen on the fixtures i have sl 36's n 19's that you can open the fixture up and what looks like change the lens position to adjust the beam (i have never opened ours up so i could be totaly wrong). I would start with a doughnut if you are not comfortable or not allowed to open the fixture.
 

falcon

Active Member
Joined
Dec 11, 2004
if you can't adjust the lenses, just get an iris kit. you can get them from roscoe or christie lights.
 

Foxinabox10

Active Member
Joined
May 1, 2004
Location
Boston, MA
Although these fixtures probably should be used from the electrics, this is pretty much all we have, so we'll have to deal with the lenses we have.

On my User Manual for the Source Fours they have a diagram at the bottom talking about lens placement, but I think all the lenses are different for various degrees. Am I accurate?
 

Les

Well-Known Member
Joined
Feb 24, 2004
Location
DFW, Tx.
I would just get some metal flashing-like material, cut it to the size of a gobo, and drill a hole in it. Experiment with different sized bits until you get the diameter of beam you want. Quite simple, really.
 

Les

Well-Known Member
Joined
Feb 24, 2004
Location
DFW, Tx.
Oh, and a donut would not work. It would have to be in the gate.
 

propmonkey

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Joined
Jul 22, 2004
Location
Milwaukee, WI
they have the different places for the lenses in the s4 barrels but you need a different lense to change the beam angle.
 

bdesmond

Active Member
Joined
Mar 8, 2004
Location
Chicago, IL USA
The widget to make your field be round rather than hard edged when the lens is in focus is called an iris. There's a slot on your S4 near the gobo slot if not in the same slot (I have little experience dealing with S4s).

As far as moving the lens around in the tube, you can't do that. The lens is actually different. It's the lens and the distance from the lamp that make the spread angle. Its a one size fits all tube, just different lenses. If you have Strand SL fixtures, look closely at the lens and on one or both side s alittle colroed drop of paint is ont eh edge - differnet color for each lens.
 

Traylen

Member
Joined
Apr 20, 2004
Location
Bay Area, California
Ok First: Though an iris kit would totally do the trick they un-fortunately cost about $120.

Also, what's wrong with "square" light? If you roll the barrel you give the edges a very frosted look without lossing intensity of the light like diffusion will do. People won't really notice the squared light if you do that. So I don't see what would be the big deal with squared light with soft edges (you usually soften the edges of all lights anyway).

However, assuming you HAVE to have rounded light for a reason I can't seem to see right now (other than specials but I doubt you're using that many specials) the only ways I can see you being able to give a rouned but small light are ethier:

a) the previously mentioned "gobo" idea, making your own or buying one
b) iris - thought quite expensive so I doubt it's even an option in your case
c) Buying new barrels for your lights (probably 50 degrees) however this will also prove costly and probably once again not the solution you seek.
d) Or possibly (never tried this) using black rap at the front of the light like a barn door but carefully shuttering the wrap to give a "rounded" effect. I don't know how well this would work, and it would look terrible and have a potential to fall off, but it's just a thought. An extrmelely far fetched thought that I probably wouldn't use, I'd probably deal with the "square" light with soften edges, assuming I had nothing else to work with and no budget.

You asked about a snoot working, and no, I don't believe it would. The purpose of snoots (aka top-hats) are to stop the spill of light from the fixture, usually used on lights that hang over the audience. I don't think they change the size of the beam and if they do, they don't change it by much, atleast not enough for what you're probably looking for if at all.

There may be other ways, unfortunately none have come to me in the time it took to write this.
 

Les

Well-Known Member
Joined
Feb 24, 2004
Location
DFW, Tx.
Yeah, there's really nothing you can do to shape the beam at the front of the light. Instead of shaping the beam, you will just be dimming it. Just wave your hand infront of an ellipsoidal (be careful!) and you'll see what I mean. Instead of seeing the shadow of your hand in the beam, ti just dims. I personally don't think there is anything wrong with square light. Infact, my area front lights are almost never perfect circles. And they're definitely never hard-focused. I would go with the plan of shuttering it into a square and rotating the lens tube 25 degrees so you get a diamond shape. Then just throw it out of focus. If the director actually notices this trick, the actors really have some work to do because obviously they aren't doing their job of keeping his/her attention. The fact is, unless you have all zoom ellipsoidals or alot of freetime, you just don't get perfect circles the exact size of your acting area from your front lights. I would just say do what you have to do to get the talent lit and move on to more exciting parts of the design. ;)