yeletah Posted March 16, 2011 Share Posted March 16, 2011 I have a question regarding gobos. I heard a rumour that there is some sort of gobo kit available which allows you to print gobos onto acetate. I can't find any information about this. Can anyone tell me whether it exists or is it just cobblers? Link to comment Share on other sites More sharing options...
david.elsbury Posted March 16, 2011 Share Posted March 16, 2011 Rosco do one, I think (the Imagepro?) but Selecon do an acetate gobo kit for the Pacific that you can use but for best results you need to use the 650w lamp bases rather than the standard 1kW bluepinch lamps. Link to comment Share on other sites More sharing options...
greenalien Posted March 16, 2011 Share Posted March 16, 2011 You don't need a kit, just a computer printer (the higher the resolution, the better - inkjet and laser both work) ,some computer transparent acetate sheet (from any stationers) and pretty much any graphics package. Problem is, acetate-based gobos aren't very heat resistant but any projection system that can handle 35mm photographic slides without destroying them should cope OK. You can improve the heat-resistance by sandwiching the acetate between 2 thin sheets of heatproof glass.If you want to make your own metal gobos, you do it the same way as making printed circuit boards, but use thin brass sheet instead of copper-coated board. Paint one side of the brass sheet, spray the other side with photosensitive etch-resist, prepare your artwork on acetate sheet, use this as a mask on the prepared brass sheet and expose it to U/V light as per the instructions on the photoresist. Then wash off the surplus photoresist and etch the metal sheet in a ferric chloride solution. Hey presto, your own gobos! Link to comment Share on other sites More sharing options...
Jivemaster Posted March 16, 2011 Share Posted March 16, 2011 Acetate "gobos" are a minority interest simply because there are few lanterns in which an acetate would have a viable life, the Pacific is the ONE that I know, unless your idea of projector includes the Kodak Carousel (in which case a 35mm glass mounted slide is better!). Link to comment Share on other sites More sharing options...
Ashley R Posted March 16, 2011 Share Posted March 16, 2011 The only fixture I know of that can take gobo's printed onto transparency, is the Selecon Pacific, loaded with a 600w Lamp, and a few other things, which I can't remember off the top of my head. If you want to make your own metal gobos, you do it the same way as making printed circuit boards, but use thin brass sheet instead of copper-coated board. Paint one side of the brass sheet, spray the other side with photosensitive etch-resist, prepare your artwork on acetate sheet, use this as a mask on the prepared brass sheet and expose it to U/V light as per the instructions on the photoresist. Then wash off the surplus photoresist and etch the metal sheet in a ferric chloride solution. Hey presto, your own gobos! Wonderful! I will have to try this some day when I need some wacky custom gobo on the relative cheap. Link to comment Share on other sites More sharing options...
Nicktaylor Posted March 16, 2011 Share Posted March 16, 2011 Actually I know it is supposed to be the low powered Selecon , but I have the 1200 version, I thought I ordered the lower powered one but ended up with the more powerful version. I have found it okay for short bursts ie a scene in a show. In answer to the Inkjet/Laser point, the latter did not work so well. The image started to "melt away" mid scene! Link to comment Share on other sites More sharing options...
the kid Posted March 16, 2011 Share Posted March 16, 2011 Get it made up on PHOTOCOPY acetate NOT printer stuff. photocopyers use a higher temp sheet because of the process. Run them at about 85/90% (make several and test what starts the melt and how long they last. We did do a show where the gobos were preset then bumped to full power to melt out for a second. great effect. Link to comment Share on other sites More sharing options...
greenalien Posted March 16, 2011 Share Posted March 16, 2011 Acetate gobos work OK with an Optikinetics Solar 250 as well, probably because the gate is fan-cooled. Link to comment Share on other sites More sharing options...
dbuckley Posted March 16, 2011 Share Posted March 16, 2011 ...unless your idea of projector includes the Kodak Carousel (in which case a 35mm glass mounted slide is better!). Oi! I resemble that remark. 35mm slide projectors are a vastly underused tool in theatre; the Carousels and similar (The Ektagraphics are better having integrated dimming) are fabulous tools, but you can do good and interesting stuff with a cheap slide projector snagged off eBay, and rewire it so that it has two plugs, one dimmable for the lamp, and one hard power for the fan and if you want it, slide changing. Print the image onto OHP film in the inkjet, and mount the trimmed image in a Gepe model 7001 glassless slide mount. Having said that, when Judas Priest did the tour to support the "Stained Glass" album, (yes, its a few years ago!) they had three pseudo-stained glass windwos projected from Carousels high above the obligatory wall of Marshalls, and it looked very amateur indeed... Link to comment Share on other sites More sharing options...
musht Posted March 16, 2011 Share Posted March 16, 2011 Orginal developer for the Selecon , David Ferguson, Fergo http://www.fergo.com.au/ Selecon`s own guide http://www.seleconlight.com/index.php?option=com_content&task=view&id=159&Itemid=211 Solar 250 will do printed transparencies as well, but better if they are moving. Link to comment Share on other sites More sharing options...
ramdram Posted March 16, 2011 Share Posted March 16, 2011 Fascinating topic and seeing as we might need some for this season..try here for more gen (usual apols if you know this already): http://www.rosco.com/us/gobocatalog/support/wattage.html Link to comment Share on other sites More sharing options...
jexjexjex Posted March 16, 2011 Share Posted March 16, 2011 My only gripe with the Imagepro is the claim the the DIY "kits" for mounting your own gobos are only supposed to be used once, ie, for a single gobo. Example - I made up a slide for projection onto a safety curtain during interval recently. Total time that the mounting and slide were exposed to heat = approx 2Hrs in 15ish minute blasts. At the end of the show run, the slide mounting still looks fine but the slide is stuck in place with bulletproof tapes I'm thinking that there must be a way of modifying these slide holders so that you can simply drop in a slide, rather than have to use a new mounting kit every time? Also, someone mentioned using copier acetate for the slide, but how well do inkjet printer inks sit on this type of film? In the bad old days of OHP's, I was always told that inkjet film was different as the ink just sat on top of the copier film. Link to comment Share on other sites More sharing options...
Don Allen Posted March 16, 2011 Share Posted March 16, 2011 For longer life of your Fergo's, put heatproof gel between the gobo and the lamp. If you are doing this in a Pacific, there are two gobo slots. This way there is an air gap between the two gobo holders. Also make sure that the ink is on the lens side of the Fergo so it is on the cooler side so it can dissipate some heat. Link to comment Share on other sites More sharing options...
GaryM Posted March 16, 2011 Share Posted March 16, 2011 And remember, just as with gels, the darker colours will burn out faster than the lighter ones. Anything printed black will burn out very quickly, so avoid if possible. I have had some very good results with acetate printed on an inkjet printer and used in a 600w pacific with one of their plastic image gobo holders. Link to comment Share on other sites More sharing options...
Jeremy MLS Posted March 16, 2011 Share Posted March 16, 2011 Acetate gobos will work fine in the 1000w Pacific. I was using a colour image of a thistle printed on to the high temperature laser printer transparancy for 8 hours a day on full for a dancing competition last year! While it did fade gradually during the day and need replacing for the next day, it never melted. The biggest saver of the gobo is having the lamp base wound down as far as it will go to dramatically reduce the heat getting to the gobo. Link to comment Share on other sites More sharing options...
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