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
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.
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 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:
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.
. . .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
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.
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.
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 - SaveFile.com project
This holds each and every update of the PDF file.
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!
END OF GUIDE
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: firstname.lastname@example.org. 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!