General Lighting Information - (LAST UPDATE: Jan. 22, 2008 6:33 P.M.)

I am going to use this thread to hold a "quick reference" of all the information that has anything to do with lighting of any kind! I will be editing this thread constantly so post any information that you want added and after I verify validity I will add it into the information. Also, if you want to know about anything involved with lighting post it and I'll find the information and update the guide. If you see someone has requested a topic to be covered and it has not, feel free to post a description and all you know about the topic and I will add it to the guide. Use this thread for any debates, tutorial links, or information links. I hope this catches on and thrives into a big lighting handbook that everyone can use! So lets get to the information!!!


Misc. Definitions:

GOBO - Wikipedia says GOBO stands for GOes Before Optics. Wikipedia - Gobo A GOBO is a piece of metal that has patterns cut into it. When placed before a light the light will produce the pattern.

Types of Lamps:
Credit: Wikipedia and Me

Fluorescent Lamp - A gas-discharge lamp that uses electricity to excite mercury vapor in argon or neon gas, resulting in a plasma that produces short-wave ultraviolet light. This light then causes a phosphor to fluoresce, producing visible light. This light is very rarely used in lighting other than to light workshops. You wont see this kind of lamp in theaters or on tours. This definition was copied from Wikipedia

Incandescent Lamp - A source of light in which an electrical current passes through a thin filament, heating it until it produces light. The more voltage you provide, the brighter the light gets. The less voltage you provide, the dimmer the light gets. This is what makes these types of lights perfect for electrical dimming(See Electrical Shutter Below). This is widely used in Stage Lighting. Most, if not all, conventional lights use this type of lamp.

Halogen Lamp - This light source is basically an incandescent lamp sealed into a small transparent vacuum that is filled with a halogen gas (like iodine or bromine). This gas makes the light slightly more efficient than a regular incandescent lamp. This type of light is widely used in intelligent lights including the American DJ DJ Scan 250HP (I own two of these!!!)

Discharge Lamp - A light source that emits light by sending an electrical discharge through an ionized gas (like plasma) These lights are hard to manufacture and they rely on the electronics to provide the correct current flow through the gas. This is why these types of lamps cannot be dimmed down electronically. These light sources usually take a little while to "strike" or turn on. That is another reason why fixtures use shutters instead of turning off the light. During an entire show the lamp is always on. This type of fixutre is widely used in intelligent lights.

L.E.D. Light-Emitting Diode. This type of light source is a semiconductor diode that produces light based upon a p-n junction. The color of the light depends on the material used in the p-n junction. For more information go to - Wikipedia - LED's

Credit: Jingles and Me

A shutter is some mechanical or electrical way of turning on/off a light. Shutters also provide the function of dimming the light(Limiting its intensity.)

There are three types of shutters:

Single-Flag Mechanical Shutter
Dual-Flag Mechanical Shutter
Electrical Shutter

Definition of Flag- A piece of aluminum attached to a stepper motor. Some have jagged edges, others are smooth. The flag is usually placed at the beginning of the optical path, right after the light source.

Definition of Optical Path- The elements placed in a light to provide a certain effect. The elements consist of colors, gobos, prism effects, shutters, etc. etc.

Single-Flag Mechanical Shutter:

This type of shutter uses one flag placed in the optical path to block the light. This provides more of an eclipse effect rather than the straight 0-100% dimming you see in dual-flag and electrical dimming. On some color wheels there is a blank spot. This is sort of like a single flag shutter with no dimming capabilities.

Dual-Flag Mechanical Shutter:

This type of shutter uses two flags placed in the optical path to block the light. This type of mechanical dimming provides the best way to duplicate electrical dimming without having to turn off your lamp.

Electrical Shutter:

This type of shutter limits the voltage running to the lamp to dim the lamp. This provides a TRUE dimming effect. This type of dimming cannot be used in fixtures using halogen and discharge lamps because the lamps are not made to be able to carry low voltage. This type of shutter is only used in fixtures with incandescent lamps. These lamps can carry low voltage with no problem.

Color Mixing:
Credit: Me

Color mixing is a way to create any possible color using different filters. There are two different types of color mixing: Subtractive and Additive. They both have their pros and cons but are both great ways to create any color on the fly!

Subtractive Color Mixing:

This type of color mixing uses multiple gels or filters to limit the light that passes through. Most CMY color mixing fixtures use this type. Three filters (Cyan, Magenta, and Yellow) are placed in front of the light source. If the light has the cyan filter in front of it it will block the red part of the light. Add the magenta filter in front of it and it will block some of the green, making blue colored light. The downside of subtractive color mixing is that if you use all three filters then you have black light, or no light. There is a way around this.

Additive Color Mixing:

This type of color mixing uses three lights, of different colors, pointed at the same point to produce a color. The lights usually consist of a red light, a green light, and a blue light (This is called RGB (Red, Green, Blue) Color Mixing.)) Since this is ADDITIVE mixing, the lights are combined to create new light. So if you have the Red and Blue lights on you will generate Purple (A.K.A. Magenta.) Now here is the way to get around the downside of subtractive mixing. USE ADDITIVE. If you turn on all lights then you get white.

Both of these are VERY prominent in the lighting world and everyone uses their own choice. Some people use both. People argue that one will have more color choice, but one shade doesn't make THAT much of a difference. Use the one you like and let other people use the one they like! Here is a picture of the RGB and CMY color wheel. If you look on the wheel you can see the Red, Green, and Blue parts of the wheel, but if you look just past those you can see cyan, magenta, and yellow. The red, green, and blue parts is what the RGB mixing uses, and the cyan, magenta, and yellow parts is what the CMY mixing uses:

DIP Switches:
Credit: LighTech and Me

Ah, DIP switches. Every newcomers nightmare. These switches often confuse a lot of people for a few reasons. One reason is because these little things use the binary code, which is used by computers. Now unless you were born when computers were invented then chances are you don't know binary code. I will not go into great detail except for the part that involves these switches.

There are usually 10 DIP switches on a fixture. There will be no less than 9. So, What are these switches used for? They are used to address a light fixture, that is to assign it a number so that it can take incoming signals from a DMX controller. So here are what all the switches equal. I'll explain what this is for after:

1 = 1
2 = 2
3 = 4
4 = 8
5 = 16
6 = 32
7 = 64
8 = 128
9 = 256

DIP switches 10+ are for special functions on that fixture. Now, one thing to notice, if you just remember that switch number 1 equals 1 then you can figure out the rest of the switches. Double whatever switch 1 equals (which is 1) and what do you get? 2! that is what switch 2 equals. Now double that and you get 4, thats what 3 equals! Now again double that and you get 8, thats what 4 equals. Just remember not to go higher than 256, or DIP switch 9.

Now how do you address a light using these. Well, these switches have 2 settings On and Off (How ironic!) Here is what you do. The object is to turn on dip switches until the numbers equal the address you are trying to get. So,tell yourself what address you want then find the number that is closest to that number but is lower than it. Make sense? Probably not, so here is an example. 52 is the address we want. 32 is the closest number and it is lower. We couldn't use 64 because that is to high. So now that you have that number turn on that DIP switch. Now you need to do that again except find the number that will ADD to the number you already have (32 in this example.) DIP switch 5 will work for us. 5 = 16 so we have DIP switch 5 and 6 on. 32 + 16 = 48.We are almost there! Now we need to find another number. Which one, when added to what we have, will get closest to the address but not go over. DIP switch 3 in our case. 3 = 4. So now we turn that on. We now have our address of 52. 32 + 16 + 4 = 52! So now that it is all said and done we have these DIP switches on - 6,5,3. The rest are off.

We can create any address from 1-512. Why 512? After you read "DMX-512 Protocol" below, you should understand it a little better. So how do you create the address of 512 when 256 + 128 + 64 + 32 + 16 + 8 + 4 + 2 + 1 = 511??? Simple! Turn all of them off! Now if I'm wrong about that please correct me! Read DMX-512 Protocol below and this will be a little more understandable. If you want to explain something a little more then just tell me and I'll fix it.

From: LighTech
. . .you also need to be aware of the European standard for DMX where all switches turned off has the DMX value of "1", and not "0". So when you are addressing certain fixtures (like Mighty Scans), you will need to address the value one less than the actual value so it takes the default additional value of "1" into account.

So, In my example of 52 above, I would need DIP switches 1,2,5,6 on if this was an European fixture.

Here are a few resources that are easy to use to figure out DIP switch settings when you are in a hurry.

DIP Switch Cheat Sheet
DIP Switch Calculator

DMX-512 Protocol
Credit: DMX512-Online and Me

This won't be a very detailed explanation because I don't know everything about it. I'm just going to explain what it is and how it works. Just the basics for this.

DMX-512 Protocol is the standard by which all lighting equipment interacts with each other. The console sends out a DMX-512 "packet" with all the information, through the DMX lines, and into the lights. This is basically what happens when you do something on the controller. Your controller sends out a signal with all the values for each channel. The lights decode this and change based upon the value of the signal. Here is a fun little real world analogy that I read on a website. I will post the link after all of this.

From: DMX512-Online

The whole system works like a city postal system. Each postman (universe) has a beat of 512 houses (channels). Each house (channel) has a unique address. Some houses are high risers with many individual apartments (several channels in one unit like an intelligent light). The postman goes from house to house and delivers the mail (the value data) in individual letter boxes. Each occupant opens only HIS letterbox and takes HIS mail. Similarly each receiving unit is told it's address (one of 512 addresses) and thus ignores all other data except the one it's supposed to receive against it's address. Some units like intelligent lights have one address as a start and go on to receive data for that address AND several more addresses FOLLOWING it . Not unlike the lobby security receptionist who takes in the mail for everyone in that building and then distributes it.

That site has ALL the info that you want (or don't want) to know about the DMX-512 Protocol. I would highly recommend you go there and read up.

So there is just a short description of the DMX-512 Protocol. If you guys want me to I will expound a little more for you. Here is that link one more time.


The Power Equation:
Credit: Jingles and Me

W / V = A

W = Watts
V = Voltage Difference (120V or 240V)
A = Amperes(Amps)

Use this equation to figure out how many amps a light will use. Here is an example:

A 500 Watt Par 56 light plugged into a 120V wall outlet uses:

W / V = A
500W / 120V = 5A

This light uses 5 Amps of power.


Wikipedia - Gobo
Wikipedia - Fluorescent Lamp
Wikipedia - LED's
DIP Switch Cheat Sheet
DIP Switch Calculator

I will try to update this info guide daily, so post any information you want to add.

Here is a link to a pdf file that you can download. This pdf includes all the information that is displayed in this thread in a more visually appealing way. I will update this link to accomodate the new pdf after an update so download the new one when the guide is updated.

PDF Links:
Here is the latest update.
General Lighting Information PDF Jan. 22, 2008 6:26 P.M.

If you want to see all of the PDF Files that I have created for this go to this link:
General Lighting Information PDF - project
This holds each and every update of the PDF file.

Coming Soon

DMX Operator 192 Basics I need some input for this idea. Do you guys want it or not?


Here I will post ideas of topics that I am ready to implement into the guide. I would like for you to tell me if this would be a beneficial thing to add or if it should be left out.

DMX Operator 192 Basics - [ ]
Is this a good idea? Tell me and I will add it in!



So there it is. Give some feedback and tell me what you think of this guide. If you have anything that you want to say to me but don't want to say it here, e-mail me at: I don't think you can PM in these forums, but if you can then do that instead. So, add topics, share your wisdom. I hope this helps a lot of people out!

Original Post
On DMX addressing via dip switches, you also need to be aware of the European standard for DMX where all switches turned off has the DMX value of "1", and not "0". So when you are addressing certain fixtures (like Mighty Scans), you will need to address the value one less than the actual value so it takes the default additional value of "1" into account.

Added Info:
DIP Switch Settings

Added LighTechs Info

Total Info:
Misc. Definitions
Types of Lamps
Color Mixing
DIP Switches
The Power Equation

Fixed Bugs:

I added the Coming Soon, Ideas, and Credits feature in this update.


Added Info:
DMX-512 Protocol

Fixed Bugs:

Special Note: I would love to hear what you guys think about this. I know it is still fairly new but I hope you guys can benefit this from this as well as I want to know what you know. I don't know everything about lighting so I want to hear what you guys know.

Total Info:
Misc. Definitions
Types of Lamps
Color Mixing
DIP Switches
DMX-512 Protocol
The Power Equation

I have started a website that holds all of this information as well so forums for the General Lighting Handbook and an all out lighting discussion. These forums are not limited to any brand of light so if you want to check them out go to My Website! You can also add your information over there and I will update it here as well as the pdf file. So check it out and give me some feedback!

Hey fellas. Long time. Anyway I need a little advice. I am looking at buying some moving head wash lights to use with my band. Already have 4 Q Spot 200's by Chauvet. I use MyDMX for control. Since I don't have front trussing (and no plans to purchase it soon) I want 2 wash moving yokes to place on each speaker stack on both sides of the stage. It would need to wash a stage by at least 20' X 30'. Would the 250 handle this or will I need to break the bank?

PS.........whens the next contest so I can win another prize (Golf shirt is still in my wardrobe).

I've got 2 of the QSPot 150's and I only feel safe putting 1 on each of my speaker stacks in a "normal" have configuration. If I rotate the horn assemblies and go "line array", I would feel no problem going 2 per side, but I only have the 2, so that has a built in limitation. It has to do with size of the speaker.

Make sure you tied down as much as possible. If you are using stands/sticks for mounting your speakers, DO NOT under any circumstances pop lights up on top of your speakers, PERIOD. It's flat out NOT safe.
We run a pretty big show. Carvin TRX speakers. Four 18's, 4 15's and Two 4" Horns per side. Each speaker weighs almost 200 pds each. Can barely lift them. I believe any size light would be secure.

I need washes. Looking also at the Martin SmartMac. Just doesn't seem to be an affordable wash (moving head) out there other than your accuwash. They will sit probably between 7 and 8 feet off the ground. Really don't want to spend more than $750.00 per light.
First time I have looked in here, lol. Boring doctor speeches will do that (that's the cause of my joining this forum too Big Grin).

Couple things, a halogen is a type of incandescent lamp. As such, it is fully dimable. The difference is that a halogen has an inert gas sealed inside the glass with the filament. This is like arc lamps, which also has gas sealed in them, but are under much higher pressures. Halogens have some pressure, but not nearly as much as arc. This is the reason for the explosion warnings on arc lamps. Because of this gas, the filament can operate at a higher temperature (aka more amperage) then a regular incandescent lamp. This is also the reason why a gas leak will cause halogens to not work, they burn out instantly/don't turn on at all. This is normally seen as a discoloration on the glass surrounding the filament.

Second, you can have more then two flags in a mechanical dimming system. This is more costly and adds complexity (A VL500A for example has 16 flags). There is also glass type mechanical dimmers seen in Vari-Lites. This, however, also causes a drop in optical quality despite being much better then a flag system (the VL2500 has less output vs the VL2000 because it uses a glass system despite being the same fixtures). There is really no such thing as an electrical shutter since halogens and incandescents can't strobe. They are instead just simply considered dimable.

Also, shutters are used for other things besides dimming lights. In ellipsoidals (lekos), they are used for framing (commonly known as Framing Shutters because of this) out the light. Some moving lights have these types of shutters in them as well.

Otherwise, good information guys.

Edit: Halogens are also used in just about every stage light. Opti Pars and Par Xs all use halogens for example. The DJ Spot 250 has a shutter/s so it can strobe, not for dimming. They might have not included a built in dimmer though, so the lamp might not dim and instead dims via the shutter/s. Trackspots, for example, actually dim the lamp when you dim them. They also have a shutter so they can strobe. They use halogen lamps as well. In fact, the only place incandescents are still used today are homes/living spaces since you can handle the lamp with your hands without shortening lamp life. They are also safe since they don't explode (I have seen halogen lamps explode before).

Much better when reading with a fresh set of eyes, amazing what one can miss. Lol.

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