dmxeater Posted August 4, 2005 Share Posted August 4, 2005 Hi guys, Our school has just bought 4 pilot 250's and in the description it says, "UV Filter"How good are the filters ? can they do a whole scene in UV picking out all the white ? Thanks for your help,dmxeater ;) Link to comment Share on other sites More sharing options...
strandgsx Posted August 4, 2005 Share Posted August 4, 2005 Hi guys, Our school has just bought 4 pilot 250's and in the description it says, "UV Filter"How good are the filters ? can they do a whole scene in UV picking out all the white ? Thanks for your help,dmxeater ;)<{POST_SNAPBACK}> a uv filter is usually placed infront of the discharge lamp to remove any damaging uv from the light output (laymens terms) otherwise you can burn your skin and eyes etc. Correct me if iam wrong Mark Link to comment Share on other sites More sharing options...
Bryson Posted August 4, 2005 Share Posted August 4, 2005 Indeed. The UV filters are there to remove UV from the beam, not to remove visible light from the beam. Link to comment Share on other sites More sharing options...
dmxeater Posted August 4, 2005 Author Share Posted August 4, 2005 Oh so I got the wrong end of the stick !thanks for the replys though, DMXEATER ;) Link to comment Share on other sites More sharing options...
paulears Posted August 5, 2005 Share Posted August 5, 2005 In this case, the UV filter Pearl River talk about is a UV simulation filter in one of the colour slots. It does make UV paint fluoresce, but also lets some visible light through - a bit like congo blue in effect. So, you can't use it to replace proper UV tubes or cannons, but it does work on UV painted cloths, costumes and scenery. In fact, it does look quite good - but the blackout you may want to achieve will be impossible. Link to comment Share on other sites More sharing options...
dmxeater Posted August 5, 2005 Author Share Posted August 5, 2005 Ah, so it would work. It's just we have 1 scene where it would require UV for props and stuff.Does that mean that you could go to Lee Filters and get that certain UV colour on a roll ? Link to comment Share on other sites More sharing options...
peter Posted August 5, 2005 Share Posted August 5, 2005 Congo Blue (Lee 181) is commonly used as an alternative to UV, although as Paul says, its not true-UV, and you will still have some visible light. For true UV, you'll need a proper UV cannon, but these are stocked by pretty much all hire companies, and are fairly cheap to hire. They cannot generally be dimmed, however, and require hard power. Link to comment Share on other sites More sharing options...
paulears Posted August 5, 2005 Share Posted August 5, 2005 Like Peter says, getting hold of true uv sources isn't too much of a problem. Mind you, I noticed UV tubes in B&Q recently and all you need are some cheap fittings - so not too expensive. Link to comment Share on other sites More sharing options...
Mush Posted August 6, 2005 Share Posted August 6, 2005 UV `simulation` filters in moving lights are sometimes referred to as Wood`s Glass filters after Professor Robert W Wood who pioneered the use of UV photography. Woods glass is also used as the filter on Blacklight Blue, fluorescent and mercury vapour lamps. Its the deep purple coating you see on these, its made by adding nickel oxide to the glass and blocks visible light form 400nM to 700nM. Blacklight in fluoros is a specific colour without a Woods glass coating, its the blueish colour used for things like aquarium lighting. Blacklight Blue, BLB, is the type of tube you want for UV effects. Would steer clear of the mercury vapour UV cannons using 400W lamps, real risk of sunburn at short range >10` Link to comment Share on other sites More sharing options...
dmxeater Posted August 6, 2005 Author Share Posted August 6, 2005 I think we'll still go for the filters but see if on the night we could hire some UV cannons. I'll proberly have to use parcans to get the brightness thought ! Thank for the replys,DMXEATER :blink: Link to comment Share on other sites More sharing options...
paulears Posted August 6, 2005 Share Posted August 6, 2005 Not sure what you mean about parcans for brightness? Link to comment Share on other sites More sharing options...
david.elsbury Posted August 6, 2005 Share Posted August 6, 2005 Talking about how he will probably use 181 Congo Blue for the UV effect, but will probably have to use PAR64s to get the brightness required. Might hire UV cannons on the night, though. Link to comment Share on other sites More sharing options...
chris.santry Posted August 6, 2005 Share Posted August 6, 2005 I'm pretty sure we had some gel in school a while back that gave a UV effect, in that it was showing up the white in clothing. I really don't know where it came from (I wasn't even aware we had it until I put it over a flood and turned it on about 5 minutes before doors were about to open for a disco). I'll try and work out what it was and where we got it from when I've next got the swatch book handy. Link to comment Share on other sites More sharing options...
paulears Posted August 6, 2005 Share Posted August 6, 2005 Congo doesn't give a UV effect? It certainly perks up whites, but it is far too visible light blue to be used in the usual UV sense? Link to comment Share on other sites More sharing options...
chris.santry Posted August 6, 2005 Share Posted August 6, 2005 It may well have been Congo, as I said, not got a swatch handy so I couldn't tell you. I can't really remember the exact shade or properties of it but I'll certainly check it out when I next can. Link to comment Share on other sites More sharing options...
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