Stage lighting basics

This document is meant as a barebones introduction to stage lighting aimed at very small live music venues. The most current version can always be found at http://www.alanrowoth.com/LightingBasics.shtml

PAR lamps

There are many new and used lighting fixtures well within the reach of a small venue. The most cost efficient is the PAR (Parabolic Aluminized Reflector) lamp . Similar in construction to an automobile headlight; these bulbs are rugged, highly efficient, maintenance free, and have a relatively long life. They are typically deployed in very low cost fixtures. They are sometimes called PAR "cans" because they contain no lenses are are basically just a can with an aluminum ring to hold the bulb in place, a bracket to aim the light and a gel frame holder in front. Disadvantages of PAR lamps include the unfocused (soft edge) of the beam, lack of precise pattern control, and inability to "project" background patterns.

Big rock shows also often use large banks of PAR64 cans. While inexpensive and efficient, these large lights may be a bit of overkill for your small coffeehouse. I'd advise looking carefully at all of your alternatives, especially PAR56, PAR46, and the new PAR20 bulbs. Here is a comparison of some of the various PAR bulb sizes.


PAR lamps contain an integral lens and reflector. The dispersion pattern is built into the bulb. The number in the name refers to the size of the bulb/8. (A PAR64 is 8" in diameter. A PAR56 is 7", etc...) They mostly range from VNSP (Very Narrow Spot) to WFL (Wide Flood) characteristics, though I have seen some specialty exceptions. Different patterns look better in different applications and you buy the pattern with the bulb, so be aware of what you are buying. Please note that all PAR lamps (except the PAR36 pinspot) have elliptical beam patterns, you shape the beam by turning the bulb within the can until the beam pattern lines up as you want it to (as well as aiming the fixure with the attached bracket.)

Narrow Spot bulbs have a much more pronounced "beam" effect and also a higher light output within their pattern, due to the concentration of the energy. Narrow spots are excellent as spot lighting where better lights are too expensive or impractical. They make a great backlight and the extra output can be used to "punch thru" those rich, deep colors that everybody wants to see on stage. They also can be backed further from the stage without spilling light off of it, if placement is an issue. But be careful, if hung too close to the stage, their tiny angle of coverage can make them almost useless.

Wide Flood Bulbs are very splashy and put out less lumens per square foot due to their wide dispersion. They are most useful in very closeup situations or where you'll be using just a few fixtures to cover a stage with light. Color Gels have different absorption characteristics with some of the darker gels passing less than 10% of the light energy. Lighter gels can help the wide flood bulbs cover more stage area effectively.
For most small club applications, I'd recommend a mix of MFL (medium flood) and NSP (Narrow spot) bulbs to cover typical situations.

Here is some info on the beam spread of PAR lamps:

Distance from target in feet: 20' 30' 40' 50' 60'

PAR 64 WFL (FFS) 10'x18' 15'x27' 20'x36' 25'x45' -------
1000 watts footcandles 85 42 26 19 -------

PAR 64 MFL (FFR) 7'x14' 10'x21' 14'x28' 17'x35' -------
1000 watts footcandles 225 150 120 100 -------

PAR 64 NSP (FFP) 6'x10' 9'x15' 12'x20' 15'x25' 18'x30'
1000 watts footcandles 390 320 150 130 90

PAR 64 VNSP (FFN) 4'6"x9' 6'6"x12' 8'x15'6" 10'x18' 13'x20'
1000 watts footcandles 430 350 210 150 100

Hope this helps!

James A. Buggie
Santa Clara University
jbuggie@scuacc.scu.edu


From: Stagecraft@zinc.com (Stagecraft mailing list)
Subject: PAR Angles
Date: Thu, 4 Aug 1994 01:56:46 -0400

Really-From: SethRR@aol.com

I'm going to whip out my Photometrics Handbook and give you what are pretty reliable averages, based on GE lamps. These are field angles. (WxH)

VNSP - 24' x 10'
NSP - 26' x 14'
MFL - 44' x 21'
WFL - 71' x 45'
(' = degree)

For those of you who don't have the Photometric Handbook, by Robert C. Mumm, I highly recommend it. It provides data sheets for just about every standard lighting unit under the sun. It cost $15, and is available through Broadway Press (800-869-6372).

Rock on!
Seth Richard Rapaport

Leko Lamps

A more surgical lighting tool is the Leko (focused ellipsoidal spotlight) . These come in a variety of sizes, usually identified by their lens diameter (and sometimes barrel length). Most common in the folk world are 3.5", 4.5", or 6" leko's, which are also sometimes called 6x9's or 6x12's. These fixtures often combine a pair of plano convex lenses with lamp shutters, a gobo (pattern) holder, and sometimes even an iris. They are VERY versatile and can be used in a plethora of ways. The focused beam can give a hard edge to the variably shaped pattern, simulating the appearance of a professional follow spot or lighting very precisely things like logo signs or specific elements of your set. They are also very attractive as a backlight and the hard edge beams look great in any kind of smoky/misty enviroment. Many theatrical productions generate "fog" to hang in the the air and show off light beams.

If leko's are so amazing, why don't we use them exclusively? First off, they are more expensive than PARs, often twice the price or more.They are also somewhat less efficient than PAR's due to absorption loss thru all of the glass and light blocked by the framing shutters. The high temperatures contribute to the much shorter bulb life of these fixtures, and the bulbs typically cost more than PAR lamps to replace. They are heavier and more fragile than PAR cans. They require more periodic maintenance and cleaning. Heck, we wouldn't use them at all if they didn't look so darn good!

A mix of PAR lamps and lekos is often the best choice for a venue adding a lighting system, with PARs providing general stage lighting and lekos for accents and spotlighting.

Legacy fixtures

There are also some legacy fixtures out there which may be available to you and prove useful depending on your situation. A lot of early stage lighting was done with Plano-Convex lamps . These feature a single lens which yields only a soft edge beam and the fixtures usually offer a minor degree of pattern control, created by changing the distance of the built in bulb and reflector to the lens. The light beam they throw is similar in character to a PAR lamp, but rounder. Many of these old style lamps feature bulbs annoted BBD (burn base down" and more care needs to be taken in the orientation of the fixture or the hot filament can sag and break prematurely. Also any theatrical lamp save the PAR tends to run at very high temperatures. You should never touch them directly with your fingers as body oils accumulate on the bulb surface and trap more head inside. This can dramatically shorten bulb life.

Fresnel lamps

Plano convex spotlights haven't been popular for quite some time. They were all but replaced by the Fresnel lamp, named after the french inventor of its stepped plano-convex lens. This innovative lens design cuts the weight and heat retention of the glass lenses and many theatrical productions still use fresnels as a staple for their very short throw lighting needs. More espensive than PARs, but less than Lekos, they are probably only worth considering if you have access to the fixtures already or can get a great deal on some used ones. They work fine though and I've paid as little as 15 dollars apiece for used fresnel fixtures. They get harder and harder to find as time goes by.

Scoop Lights

Scoop lights (also sometimes known as "Cyc's" which is pronounced like "Psych!") offer no pattern control. They are large and can cost close to $100 each new. They are also very splashy and use like 24 times as much gel material compared to a 6" fresnel. They are sometimes useful to light the backdrop of your stage area (cyclorama) either from the rear or the front. Normally I don't recommend them to folks unless they already have a couple of fixtures, but I've seen people use them as general stage fill in a pinch. Mounted very close, but out of audience view. They are probably too large for a musician to travel with, but might not be bad in a fixed installation.

"All I can see is lights...

It's important not to blind your audience by aiming your stage lighting right into their eyes. Placement is usually the best solution to this problem. If you use a lot of backlighting be sure that the coverage patterns of the lights are on the stage, not in the audience. Getting the lights up higher may help you to accomplish this. You can also purchase auxiliary lighting baffles, (often called "barn doors ") that attach to the lighting instrument's gel frame holder and can be used to further control the pattern. These won't put a hard edge on a soft edged beam, but they are still very useful. Sometimes you'll see a fresnel with what looks like a can hanging from the front of it. These are called "snoots" and they give the fresnel a bit more of a PAR light appearance. Even with a snoot, fresnels won't approach the directivity of a VNSP PAR.

Where do I plug them in?

This is the big question for a lot of venues adding lights and can sometimes be the most expensive part of the equation. Much of the mood of theatrical lighting comes from "gelling" the lights to certain colors. By filtering much of the spectrum out of the beam, you get these great looking rich colors. Unfortunately, you are also discarding much of the output of the bulb. Theatrical fixtures tend to run in wattages from 200 watts up to 2000 watts or more, with most PAR64 cans in the 500-2000W range, PAR56's in either 300 or 500 watt sizes, and PAR46's running around 200 watts per bulb. Lekos tend to run 500-1000 watts per fixture.

Your average electrical circuit is about 20 amps, which can supply roughly 2400 watts. That means that you can figure about 4-6 PAR56's on a 20 amp circuit or maybe 3 or 4 lekos. In a typical club you might use 5 circuits total for the performance. One 20 amp for the stage gear, one for the sound system, and 3 circuits for the lights. When I was travelling with the rock band, we used to carry an entire 160 amp electrical service around with us that we would attach at the service entrance of the night clubs and run 16 seperate circuit breakers for just our lights. The feeder cable that ran up to our breaker box was almost an inch and a half thick. It took two guys to lift it onto the truck. That was overkill, even back then... (But we were that kind of band...) If you have 3-20 amp circuits for lights, you could put 4 -300W PARS and 2 -500W PAR's for front/side fill light on one, The same complement on another circuit for backlighting, and still have a circuit for 3 or 4 leko's up front to cover the singers and soloists in the group.

If you are unsure if you have enough power of that it's properly distributed, be sure to turn all the lights on and crank up the sound system and let them cook a little before you try to do a show with your system. You may have to talk to an electrician if you need additional capacity.

What about dimmers?

Dimmers are cool. Most home dimmers are a maximum of 500 watts each and may cause guitar pickups and other electronic equipment to buzz. These are cheap at the hardware store, but I'd advise you to stay away from them.

Professional dimmers typical include what's called a "zero crossing detector" which keeps the noise out of the sound system and professional dimmers usually run 1200 to several thousand watts per "channel." They can be little expensive up front, but they add a wonderful range of subtle dimension to your lighting schemes. Better boards have 2 or more dimming "presets" that allow you to premix scenes and crossfade smoothly from one lighting scheme to another. Most professional music shows use this type of lighting to good effect and it will add a touch of professionalism to your work if you do the same. If you are strapped for cash, start with fixtures and add dimmers as you can.

How about those Gels?

I'm so embarrassed. I never really took any color theory and don't have any magic formulas on what colors to use. I know that green looks really bad on faces from the front , but can make for a cool looking back light. Everybody loves blue lights, expecially Deep Blue, but these gels tend to have the lowest light transmission factor. You need lots of lights and lots of power to turn a stage bright deep blue. (also very dark gels tend to become brittle and "burn out" faster. Sometimes it's easier to go with a "bluish" gel for some lights and leave it at that.

The best known gel manufacturers is Rosco. Any theatrical lighting store will be able to sell you a color swatchbook to that you can browse to select your gel colors. Amber and red family gels often have lower transmission loss while still yielding rich colors. We would often put two front fill fixtures on the same dimmer channel with complementary gel colors instead of matching the gels. This gave the performers a bit more depth and made it look like we had more lights than we actually did. Also some colors work better together than others, be prepared to experiment a little until you get your color scheme right.

White light is an effect. Don't overuse it and it can be a very effective tool, especially in a backlight situation. Most spotlights should be a bright color, but a nice bastard amber or rose can be much more flattering on skin tones than pure white which tends to make Anglo complexions look sallow.

A couple of other tips.

• Any light mounted lower than eye level is going to cause garish shadows on your face. This can be a useful effect, but generally it's a bad idea.
• Backlighting can be particularly effective if it highlights the outline of the performer so they stand out more from the backdrop of the stage.
• Black backdrops and walls soak up a lot of light, making your patterns more controllable if you have the fixtures to cover that. White (or other highly reflective) walls or ceilings will reflect more light and the stage will be brighter, but less dramatic looking.
• Never "double up" gels. They'll get very hot and wear out in no time. It's better just to buy the color you need. There are hundreds of colors available.
• Another tip some theatre geek showed me was to prick a bunch of holes in all of our new gels with a straight pin. (like a tiny pot pie...) You never see the teensy holes and the gels seem to accumulate less heat, breathe better, and last longer.

A few useful Links

 

Yahoo links to stage lighting pages
The Great Internet Light Bulb Book, Part I
Don's Lighting Info Center
Brendan's Page for Lighting Designers
Strand Lighting Home Page
Rosco - Gels (color filters)

I'd like to expand this document to cover many more aspects of stage lighting on a shoestring. I'd love to hear from you about what was helpful and what you needed to hear more about.