I really need some advice.

[misterd]

Hi there,

I'm a high school senior handling lighting for a new black box theatre for a community theatre (seats about 60).

I was given ten lekos at 1000w to light the small stage-- only problem is that our space is limited, so that my lekos are, on a diagonal, about 20 feet from the front edge of the stage.

Pathetic cross-section:

In addition to having a really uneven illumination (spotlighting created by lekos is easily seen), there are a lot of shadows. I just really don't know what to do to get the set and the actors illuminated well with this setup.

How can I reduce shadows and reduce visible spotlighting?
Thanks so much in advance.

-Shaun

 

[avkid]

Is that your only viable position?

 

[misterd]

Unfortunately, yes. My C-truss is a quarter inch off the ceiling, and is as far back as feasible.

 

[techieman33]

Unfortunately, yes. My C-truss is a quarter inch off the ceiling, and is as far back as feasible.

We're thinking more along the lines of side lighting. Are all of your lights clustered in the center? Can you spread them out some more? And as far as "spot lighting" you just need to soften the focus and if that isn't enough you can add some diffusion. Something along the lines of an R132 to start.

 

[derekleffew]

I suspect the ERS lights you have are too narrow. Ideally you'd want 50° (4 1/2 x 6 1/2); second best 36° (6x9). As said above, some diffusion media will even out the hot spots, but I'd use Roscolux 114 or 119 rather than 132.

 

[kicknargel]

You could also think about moving the lights farther to the side and cross-lighting rather than straight on. This will increase the throw somewhat. Or try to trade for/buy a more appropriate fixture.

 

[icewolf08]

As far as your shadows go, they will always be a problem unless you can get lights above the stage for top/back light and for some sides light. It would be great to know what fixtures you have and how big the stage is, might allow us to be more helpful.

 

[misterd]

Thanks for the responses! I really appreciate it.

My lights are indeed spread out. I'll work on softening the focus and purchase a sheet of RS119 or similar. If that doesn't help enough, can I buy "wider" lenses or would I have to purchase all new lights?

If that's possible, how much do new lenses typically cost?

Thanks again, everyone.

 

[smigit2002]

Costs all depend on the availability of parts, which depends on the type of fixture. Additionally, we could give better suggestions as to beam angle if we knew the dimensions of the stage.

 

[misterd]

Alright: the stage is approximately 32' x 15'.

All I know right now is that they are Strand LekoLites, but I'm going to head over there soon, so I'll post something more detailed when I get back.

Maybe you all could help: they're black, rounded yolk, circular body. They're definitely not new, but were kept in great shape so I'd have a hard time approximating their age. There is a tension knob that allows the bulb assembly to be moved forward and back on the top of the instrument, and the lens has a similar knob at the very front of the instrument.

Thanks so much for taking the time to ask questions, everybody. I really appreciate you all taking the time to help me out.

 

[derekleffew]

...All I know right now is that they are Strand LekoLites, ...

Know (and love) them well.

Model numbers are:
2204 - 4.5 x 6.5
2209 - 6 x 9
2212 - 6 x 12
2216 - 6 x 16
2112 - 6 x 12 single lens (15°)
2113 - 8 x 13 (10°)
2123 - 10 x 23 (5°)
and later a couple of zoom models.

Introduced by Strand-Century about 1979 (fixtures made after 1989 say Strand Lighting) and made until about 1992. Look for a metal label on the lens tube. It'll tell you what lenses are in it.


As I said above, ideally you'd want it to say "2 - 4.5 x 6.5 P.C. Lenses" or "2 - 6 x 9 P.C. Lenses". If it says 6x12 like the one pictured, the lenses could be changed; but to buy new would be ~$65 each, and you need two per fixture!

 

[Les]

Know (and love) them well.

Introduced by Strand-Century about 1979 (fixtures made after 1989 say Strand Lighting) and made until about 1992. Look for a metal label on the lens tube. It'll tell you what lenses are in it.

...And unfortunately, I don't believe wider lenses can be used effectively. Like the Altman 360Q, the lenses used will have to match the length of the barrell.

 

[derekleffew]

Les, this particular line of fixtures (and the gray diecast radial model that preceded it) used a lens tube that could accommodate 4.5x6.5 (with an adapter), 6x9, 6x12, 6x16. The barrels all measure ~6"; the extra length needed is achieved via the sliding dog in the lens tube.

Rather ingenious, and only slightly annoying when trying to replace the lens focus knob (getting the dog to stay still in one place).

 

[misterd]

Thanks for the detailed info.
$130 per light in not an option (I don't think $30 a light is even an option!), but thank you for ruling that out for me. Now I can focus on doing the best with what I have.

Any other advice besides using a diffuser, focusing softly, and crosslighting?

Thanks everyone.

 

[derekleffew]

...Any other advice besides using a diffuser, focusing softly, and crosslighting?

That's pretty much it for the optical/photometrics portion. Note: you either want to soften by running the lens, or keeping the lens sharp and adding diffusion media. Nothing to be gained really by doing both.

EDIT: You mentioned the lamp adjustment which slides the lamp forwards or backwards in the reflector (also known as peak distribution/cosine distribution adjustment). Adjust so the field is as flat and even as possible (cosine), then use the lens or diffusion to soften the edge. Setting the lamp to "peak" will make the center brighter, but will add to your "hot spot" problem. Also on the back of the lamp cap is a three-sided joystick knob for adjusting the X-Y. Make sure the hot spot is centered. One of the criticisms of this line of fixtures is that you have to bench focus the fixture with every lamp change. I call that a feature, as one should bench focus a fixture with every lamp change. (Though lamp manufacturing tolerances and filament design are much better today than they used to be.)

Earlier you said "1000W Lekos"; do you actually have 1000W FEL lamps in them? Hard to imagine you NEED that high of wattage. Most here would recommend transitioning over to the 575W, 1500-hour, GLA lamp. The 500W EHD and 750W EHG lamps work okay, but are of an older filament design.

 

[misterd]

Alright. I've convinced the director etc. to move the stage back.

The question now is how far do I need to move the stage back?

Would 20' be enough? I'll need to know exactly how far to move it because I won't be able to test out different distances live (it needs to be disassembled to be moved).

How would I calculate something like this?

Thanks for your help, everybody. Seriously, I really appreciate it.

 

[shiben]

Alright. I've convinced the director etc. to move the stage back.

The question now is how far do I need to move the stage back?

Would 20' be enough? I'll need to know exactly how far to move it because I won't be able to test out different distances live (it needs to be disassembled to be moved).

How would I calculate something like this?

Thanks for your help, everybody. Seriously, I really appreciate it.

Depends on the size of your lenses. If they are 36s, you can probably get away with like 5-10'. 20' would probably do the trick no matter what. Now to calculate the distance to move, use this information: Trigonometric functions - Wikipedia, the free encyclopedia To figure out your throw distance (the Hypotnuse). An easier way to do this if you are not decent at math (like myself) is to use a CAD program and make a basic diagram of a triangle, and figure out your lights. With this functionality, you can determine beam size (using the same functions and knowing the beam and field angles) and if your wash will be enough to cover the stage. Vectorworks and LD Assistant will usually be able to do this for you, but you can do it by hand if you want, and that will also help you understand what you are actually doing.


Sort of what I would do on CAD for finding the throw distance:

Picture 8 | Flickr - Photo Sharing!

Often, manufacturers will give data on the photometrics of their instruments either on the Web or in print form somewhere. To get a beam size, do the same thing, but make a cone with the pointy bit the angle of the instrument (beam angle is the one you want, I believe, correct if wrong), and line the axis of the cone on the throw distance. It is generally good practice to set your focus points around head height (5' is usually a pretty good and easy to set approximation), so take that off your trim. Since this drawing is actually in half inch scale, you can then measure how large your pool size will be, at least on the US/DS axis. You can do something similar for the SL/SR axis and then draw an ellipse using those dimensions.

 

[derekleffew]

Whoa there, Mister D! Moving the stage to accommodate the photometrics of the luminaires is an unprecedented undertaking and requires some serious thought and careful study.

1. You still haven't told us what fixtures you have (lenses).
2a. In the drawing below, you want to know H, the horizontal distance from the lighting position to the front of the stage.
We (and you) will also need to know V and S.H. and desired A. of E. to find H.
2b. If A. of E. is based on the actor standing centerstage, it will be higher when he moves DS and lower US.
2c. If using front lights 45° left and right of center (see McCandless method), T.D. (throw distance) will be increased by a factor as much as 1.414.
2d. Precise drafting skills, as well as how various angles of light reveal form (Functions of Light #2) (look in any lighting textbook and at An Analysis of Lighting Angles – Frontlight « Light Cue 23 ) is paramount.



I'd say it's much easier to do some rehanging/refocusing and maybe adding R114, before even considering moving the stage.

 

[shiben]

Doing some more work on this, things to remember: Your not actually interested in the distance from the stage edge to the pipe, but rather the pipe to the focus point. In the example linked to earlier, when a 36º beam angle is superimposed on the angles, you end up with a 37' deep pool (US/DS Axis), and if I did it right, only a 15' - 6" wide pool (SL/SR axis). From that you can draw out your curves to figure out the shape of the pool, roughly. These are pretty rough numbers, not sure how the field on a lekolight works, but the point is this, you can figure this out without a computer even. Just grab the photometrics for your instruments, and use the beam angle for your calculation.


Note: If Im doing this wrong, let me know. I tend to use the "draw beam" function of Vectorworks, so Im a bit rusty on a 2 year old class on hand drafting...

 

[shiben]

Whoa there, Mister D! Moving the stage to accommodate the photometrics of the luminaires is an unprecedented undertaking and requires some serious thought and careful study.

1. You still haven't told us what fixtures you have (lenses).
2a. In the drawing below, you want to know H, the horizontal distance from the lighting position to the front of the stage.
We (and you) will also need to know V and S.H. and desired A. of E. to find H.
2b. If A. of E. is based on the actor standing centerstage, it will be higher when he moves DS and lower US.
2c. If using front lights 45° left and right of center (see McCandless method), T.D. (throw distance) will be increased by a factor as much as 1.414.
2d. Precise drafting skills, as well as how various angles of light reveal form (Functions of Light #2) (look in any lighting textbook and at An Analysis of Lighting Angles – Frontlight « Light Cue 23 ) is paramount.

View attachment 4617

I'd say it's much easier to do some rehanging/refocusing and maybe adding R114, before even considering moving the stage.

And his diagram is better than my explanation. Also, based on your information, assuming 40º instruments, you just need to focus them better (by my rough drawing work. Im getting about 10' wide pools that are like 22' deep at 18' trim [at a 5' focus point]).

Moving the stage is a lot of work. However, if these are the ONLY lights you will ever get, and you really cant afford to buy new lenses, moving the stage might be the best option for the long run, as the next LD will probably run into the same problem.