Community Theater Green Room Discussion Board: Gobo questions

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Kim L.
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Joined: 2/03/07
Location: United States
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Posts: 86

Topic: Gobo questions
Posted: 1/01/08 at 9:04am

Is it expensive to rent gobos?

I have seen some rather cheap on ebay. Is it worth purchasing from them?

Also, I might be able to use a gobo in my middle school production, which has virtually no budget. Can I stick a gobo in front of a domestic spot light and get an effect? By domestic spot, I'm referring to the type of light you shine on your house at Christmas time. For our middle school production, we are having the play in a gymeatre.

Thanks!!

Kim

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vickifrank
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Joined: 9/21/07
Location: United States
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Posts: 332

Posted: 1/01/08 at 11:01am

Purchasing Gobos runs from about $5 to thousands. The difference is that you can buy standard steel cut gobo patterns for $5-12. Custom steel cut gobos cost more. Glass black and white gobos cost more. Glass custom full color custom gobos cost in the thousands. These allow the projection of one full color image.

----

There are three main differences between architectural lights (that you can purchase for your home) and professional theatrical lights. Theatrical lighting needs these things, the first two you can overcome with homemade solutions--its the last one that you can't use well with a home flood light:

1.) You need to be able to mask the light. Simply stated this means you need a way to block the light from falling where you don't want it. This can be curtains, barndoors (metal flaps on the front of lights that adjust like a barndoor by swinging in), snoots (look like coffee cans on the front of the light, not surprisingly you can use coffee cans!)

2.) You must be able to control the lights independantly. For most people this means making a simple light board control.

3.) You need to focus the lights. Focusing the light moves a lens in front of the light to be able to throw the light a certain distance and control the spread of light. This is similar to what you do by twisting the ring on the outside edge of the household flashlight. This is what would be difficult with a flood light.

With a flood light the light is designed to spread out (floods the house) instead of focusing. This would most likely make the gobo image fuzzy, not focused and sharp. The other thing is that you would have no built in place to attach the gobo. And heat build up is a fire hazard.

So can you do it? Sort of. It won't be nearly as good or usable. You will end up having to move the light to get the gobo image the right size, which might place it in a bad place.

If you want to make a simple test, take an aluminum pie plate, cut a simple shape in it and place it six inches or more in front of your flood light (you must give it several inches space for air movement and be aware that this will get really hot very fast)

A better choice may be to see if you can borrow a light tree and some real lights from the local high school. You may be able to borrow the gobo there too.

There's are articles on my website for instructions and pictures of barndoors and snoots: http://www.studio-productions-inc.com/white_papers/wp_canido_main.html and http://www.studio-productions-inc.com/white_papers/wp_photo_lighting.html These are not written exactly for your question, but provide some background. The first talks about whether you can use hardware store-type lighting in one section. The second shows some light control devices used in photography, which can be used in theater as well-gobos, flags, barndoors, snoots--including pictures.

_____________

http://www.studio-productions-inc.com
1-800-359-2964

The theater scrim people

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JoeMc
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Joined: 3/13/06
Location: Australia
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Posts: 832

Posted: 1/03/08 at 4:26pm

Just adding to Vicki's great reply.

Placing a gobo [or Bogo - which is more apt in theatre parlance!]

in front of a domestic lamp [flood] won't work, as bogo's need to be between the lanterns optical lens & light source [bubble - globe] to be effective.

What you were thinking of is more like the old 'Linnebach' siloutte system.

Where an image is placed at the front of a flood to project a cut out image on to the upstage of a drop cloth.

However the flood had no reflector, which would have distorted the beam & image.

Back in the 50's, we made up our own glass gobo's, by printing a photographic image from a negative on to a piece of glass, cut to size. However these were some what fuzzy, but worked at the time.

You can make up your own, from an old printers offset plate, if you can still get them theses days/ [as they are paper plates now] or use some alluminium shim plate.

Draw your required image on a piece of paper, place it on a sheet of carbon paper. Then place the paper image & carbon paper on to the plate.

Draw around the image outline with a pen & transfer the carbon image onto the plate. Cut it out using a craft knife & cut the plate to the sizes of the lamps gobo slot or holder.

On the other hand you could use the Selecon Pacific lamp, which has a unique heat dissapation system, allowin plastic gobos to be used.

Selecon Lighting 'Pacific' range;-

http://www.seleconlight.com/index.php?option=com_content&task=view&id=159&Itemid=211

The image can be prioduced from your PC onto Mylar [Overhead Projector clear plastic sheet} cheaply to great effect.

These Profile lights can be hired in for the production. [Made in New Zealand] from local theatre lighting agents in your area.

However if you only reqire a 'breakup' image, you can use a Fresnel [soft edge sot] or flood, with a sheet of filagre pierced metal [Air Con duckt plate with a heap of holes in it] wrapped over the front of the lens, which will project a breakup patten onto the area required.

[western] Gondawandaland
"Hear the light & see the sound!
TOI TOI CHOOKAS
{may you always play to a full house!}

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Lights and Sound
Community Theater Green Room Discussion Board :Producing Theater :Lights and Sound

Author	Message
Kim L. Star Joined: 2/03/07 Location: United States Online Status: Offline Posts: 86	Topic: Gobo questions Posted: 1/01/08 at 9:04am
	Is it expensive to rent gobos? I have seen some rather cheap on ebay. Is it worth purchasing from them? Also, I might be able to use a gobo in my middle school production, which has virtually no budget. Can I stick a gobo in front of a domestic spot light and get an effect? By domestic spot, I'm referring to the type of light you shine on your house at Christmas time. For our middle school production, we are having the play in a gymeatre. Thanks!!
	Kim

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vickifrank Celebrity Joined: 9/21/07 Location: United States Online Status: Offline Posts: 332	Posted: 1/01/08 at 11:01am
	Purchasing Gobos runs from about $5 to thousands. The difference is that you can buy standard steel cut gobo patterns for $5-12. Custom steel cut gobos cost more. Glass black and white gobos cost more. Glass custom full color custom gobos cost in the thousands. These allow the projection of one full color image. ---- There are three main differences between architectural lights (that you can purchase for your home) and professional theatrical lights. Theatrical lighting needs these things, the first two you can overcome with homemade solutions--its the last one that you can't use well with a home flood light: 1.) You need to be able to mask the light. Simply stated this means you need a way to block the light from falling where you don't want it. This can be curtains, barndoors (metal flaps on the front of lights that adjust like a barndoor by swinging in), snoots (look like coffee cans on the front of the light, not surprisingly you can use coffee cans!) 2.) You must be able to control the lights independantly. For most people this means making a simple light board control. 3.) You need to focus the lights. Focusing the light moves a lens in front of the light to be able to throw the light a certain distance and control the spread of light. This is similar to what you do by twisting the ring on the outside edge of the household flashlight. This is what would be difficult with a flood light. With a flood light the light is designed to spread out (floods the house) instead of focusing. This would most likely make the gobo image fuzzy, not focused and sharp. The other thing is that you would have no built in place to attach the gobo. And heat build up is a fire hazard. So can you do it? Sort of. It won't be nearly as good or usable. You will end up having to move the light to get the gobo image the right size, which might place it in a bad place. If you want to make a simple test, take an aluminum pie plate, cut a simple shape in it and place it six inches or more in front of your flood light (you must give it several inches space for air movement and be aware that this will get really hot very fast) A better choice may be to see if you can borrow a light tree and some real lights from the local high school. You may be able to borrow the gobo there too. There's are articles on my website for instructions and pictures of barndoors and snoots: http://www.studio-productions-inc.com/white_papers/wp_canido_main.html and http://www.studio-productions-inc.com/white_papers/wp_photo_lighting.html These are not written exactly for your question, but provide some background. The first talks about whether you can use hardware store-type lighting in one section. The second shows some light control devices used in photography, which can be used in theater as well-gobos, flags, barndoors, snoots--including pictures.
	_____________ http://www.studio-productions-inc.com 1-800-359-2964 The theater scrim people
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JoeMc Celebrity Joined: 3/13/06 Location: Australia Online Status: Offline Posts: 832	Posted: 1/03/08 at 4:26pm
	Just adding to Vicki's great reply. Placing a gobo [or Bogo - which is more apt in theatre parlance!] in front of a domestic lamp [flood] won't work, as bogo's need to be between the lanterns optical lens & light source [bubble - globe] to be effective. What you were thinking of is more like the old 'Linnebach' siloutte system. Where an image is placed at the front of a flood to project a cut out image on to the upstage of a drop cloth. However the flood had no reflector, which would have distorted the beam & image. Back in the 50's, we made up our own glass gobo's, by printing a photographic image from a negative on to a piece of glass, cut to size. However these were some what fuzzy, but worked at the time. You can make up your own, from an old printers offset plate, if you can still get them theses days/ [as they are paper plates now] or use some alluminium shim plate. Draw your required image on a piece of paper, place it on a sheet of carbon paper. Then place the paper image & carbon paper on to the plate. Draw around the image outline with a pen & transfer the carbon image onto the plate. Cut it out using a craft knife & cut the plate to the sizes of the lamps gobo slot or holder. On the other hand you could use the Selecon Pacific lamp, which has a unique heat dissapation system, allowin plastic gobos to be used. Selecon Lighting 'Pacific' range;- http://www.seleconlight.com/index.php?option=com_content&task=view&id=159&Itemid=211 The image can be prioduced from your PC onto Mylar [Overhead Projector clear plastic sheet} cheaply to great effect. These Profile lights can be hired in for the production. [Made in New Zealand] from local theatre lighting agents in your area. However if you only reqire a 'breakup' image, you can use a Fresnel [soft edge sot] or flood, with a sheet of filagre pierced metal [Air Con duckt plate with a heap of holes in it] wrapped over the front of the lens, which will project a breakup patten onto the area required.
	[western] Gondawandaland "Hear the light & see the sound! TOI TOI CHOOKAS {may you always play to a full house!}
	IP Logged

Topic: Gobo questions( Topic Closed)