Conventional Fixtures ETC Source Four 26 or36 with 750watt lamp

[gowings]

I'm confused:
I am trying to wrap my head around what degree to buy in the source four line. 26 or 36 degree. Gobo colour image will be projected approx. 18 feet with a 750 watt lamp. If the degree is larger say the 36, does the image become not as sharp at the surface it is hitting. Footcandles would be better with the 26 if I understand the chart with a hit image on the surface of 9 feet. If I go with the 36 then the image becomes weaker because the beam is wider at the intended surface of 18 feet and FC is lower. The intent is to project a black and dark green image onto a dull white surface almost grey in nature.

 

[DuckJordan]

It's all about how large you want the projected image to be. The 26 will be smaller, where the 36 degree will ve larger (projected image).

Sent from my ADR6300 using Tapatalk

 

[gowings]

Do I lose clarity at the 36 and bigger image. I want big if possible

 

[chausman]

Do I lose clarity at the 36 and bigger image. I want big if possible

If you can, you could get the EDLTs for it. Those would have the best clarity. http://www.etcconnect.com/minisite/sourcefour/edlt.html

 

[jglodeklights]

You will lose sharpness with the 36, but only because optically the 36 isn't quite as good as the 26. You also lose some clarity, depending on the levels of light hitting the surface not from your fixture projecting the gobo, because, as you stated, the 36 is dimmer as it is spreading the light from the lamp/reflector over a larger area. Both the 26 and 36 are available in Enhanced Definition form which uses better quality glass and optical design to increase sharpness of projection, and additionally a donut (a sheet of metal with a hole in it placed in the front colorframe slot of the fixture) to improve sharpness at the cost of intensity.

 

[derekleffew]

...The intent is to project a black and dark green image onto a dull white surface almost grey in nature.

This in and of itself is problematical, as one cannot project a black image. By definition, black is the absence of light.

...and additionally a donut (a sheet of metal with a hole in it placed in the accessory slot of the fixture) to improve sharpness at the cost of intensity.

Donuts go in the colorframe slot. Most people refer to the slot with the sliding door intended for an iris, thick glass gobo, or gobo rotator as the accessory slot. Confusingly, a top hat or color extender is an accessory, but they don't go in the accessory slot.

 

[shiben]

This in and of itself is problematical, as one cannot project a black image. By definition, black is the absence of light.

Donuts go in the colorframe slot. Most people refer to the slot with the sliding door intended for an iris, thick glass gobo, or gobo rotator as the accessory slot. Confusingly, a top hat or color extender is an accessory, but they don't go in the accessory slot.

I thought they went in the forward accessory slot, or is that supposed to be "Color 2"?

 

[jglodeklights]

*Thumwmph* Joe Fail. You're right. I mean *FRONT* Color Frame slot.

 

[jglodeklights]

I thought they went in the forward accessory slot, or is that supposed to be "Color 2"?

That is another name people use for it. However, not all fixtures have a forward accessory slot or second color frame slot, and thus donuts and other accessories go in the front most colorframe slot or just the colorframe slot. And I'm sure someday someone will (if they haven't already) introduce a fixture with two accessory slots *bug eyes*. Also, in houses with rep plots that change color often, many people will leave a cut of frost in the rear slot and only change out the front *actual* color. This slightly increases gel life, and to further it people will leave a cut of heat shield in with the frost.

 

[shiben]

That is another name people use for it. However, not all fixtures have a forward accessory slot or second color frame slot, and thus donuts and other accessories go in the front most colorframe slot or just the colorframe slot. And I'm sure someday someone will (if they haven't already) introduce a fixture with two accessory slots *bug eyes*. Also, in houses with rep plots that change color often, many people will leave a cut of frost in the rear slot and only change out the front *actual* color. This slightly increases gel life, and to further it people will leave a cut of heat shield in with the frost.

Im not sure how useful accessory slots would be, as only one of them could really be in the focal plane...

 

[jglodeklights]

All depends on how you use 'em my friend. When you are using a gobo, it doesn't perfectly line up with the focal plane, thus why when you shutter with a gobo only one or the other can be sharp. A rotator with a DMX iris could be useful to make some fun movements when combined with a Right Arm or I-Cue....

 

[shiben]

All depends on how you use 'em my friend. When you are using a gobo, it doesn't perfectly line up with the focal plane, thus why when you shutter with a gobo only one or the other can be sharp. A rotator with a DMX iris could be useful to make some fun movements when combined with a Right Arm or I-Cue....

This is true... I guess im more of a sharp gobo guy meself so there is that...

 

[josh88]

but soft focused gobos just make such nice texture!

 

[jglodeklights]

Yeah, although when you throw R119 in there the texture might be more of a JND.

 

[shiben]

but soft focused gobos just make such nice texture!

They do, but all the shows I do seem to be "dreamy and surreal" which make for sharp texture in haze. Go figure.

 

[gowings]

Gobo with a Stars Pattern

I am cutting down the budget. Instead of a 400 buck glass gobo custom made of a full color logo. I am investigating a glass or metal gobo showing Forest Green Stars. Can you give me advise on what will work. Would gel work in this case along with a metal gobo to create the effect. This is a source four 750 watt 26 degree fixture maybe on 5 mins. at a time at the beginning of the show then intermittent for 45 seconds through the night say 7 times, Twice a week, for 12 weeks. If I use gel how often would I have to change it or is a 1 color glass gobo the way to go.
Thanks for your reply's

 

[josh88]

Re: Gobo with a Stars Pattern

just put the gel in the normal spot on the s4 (dont try to put the gel on the gobo) and it will work fine. Find the stars you want in metal, find the color green in the gel book and you're set. even if you had to change the gel once a week which you shouldn't it would be cheaper than a glass gobo. depending on how dark it is, you buy one sheet of gel which is 20x24 so you'll get 6 cuts per sheet for about $7 and the cost of the gobo. thats a change every 2 weeks if it burns through that fast.

 

[gowings]

Re: Gobo with a Stars Pattern

Where do I find a gel book for color reference and ordering. Any thoughts on a reasonable and respectable gobo maker for a Stars Gobo

 

[derekleffew]

Re: Gobo with a Stars Pattern

... one sheet of gel which is 20x24 so you'll get 6 cuts per sheet ...

My iPhone app tells me that a 20x24 full sheet will yield nine (9) cuts of 6.25x6.25 for a Source Four 26°.

Where do I find a gel book for color reference and ordering. Any thoughts on a reasonable and respectable gobo maker for a Stars Gobo

Color media, and a stock or custom gobo manufactured by Rosco, Lee, GAM, or Apollo, may be purchased from Dealers for Supplies and Equipment - ControlBooth . You may obtain a swatchbook from the same sources.

Is something like this what you had in mind?

Super Stars MS-2553

If you're looking for something a little/a lot more realistic, projecting a gobo may not be the best way. See also http://www.controlbooth.com/forums/special-effects/4570-star-curtains.html and http://www.controlbooth.com/forums/special-effects/14789-another-star-curtain-question.html .

 

[josh88]

Re: Gobo with a Stars Pattern

I tend to aim low because of miscuts or different sizes... and because I KNEW you could get six, and didn't feel like doing the math any closer than that hehe.

Rosco will do the gobo and the gel, it's easiest to find a dealer off the list Derek linked. I most recently ordered both through norcostco and had no complaints.

Rosco US : Gobos just search for stars here and you can see what they've got for premade stuff

and while I prefer to actually have a swatch book so that I can look through the gel held up to light, you can go here to see the rosco colors.

Rosco US : Filters : Roscolux


that being said, Derek listed a handfull of companies and you should just troll through their sites until you find a gobo you like, and are happy.