rob_cheese Posted January 12, 2008 Share Posted January 12, 2008 I recently read a book with a chapter on dichroic filters, which I'd not heard of before, and subsequently read more online. Is it possible to get hold of dichroic filters for Strand Codas? I guess it'd be tricky to replace a gel with a piece of glass, but a lamp with a dichroic coating might work...? Cheers Rob Link to comment Share on other sites More sharing options...
maeterlinck Posted January 12, 2008 Share Posted January 12, 2008 Humm, that's a big piece of expensive glass... Gel not working for you? Link to comment Share on other sites More sharing options...
gareth Posted January 13, 2008 Share Posted January 13, 2008 Gel not working for you?Quite - what's wrong with Lee, Rosco and Gam? What application are you using the Codas for which is demolishing regular colour at such a rate that you need to look at dichroics? They're very expensive, and only really justifiable if you know you're going to be using the same colour in a fixture for an extended period of heavy use, IMHO. Apart from anything else, the colour frame on a Coda is curved, and you ain't going to get a piece of dichroic filter that shape! Link to comment Share on other sites More sharing options...
Jivemaster Posted January 13, 2008 Share Posted January 13, 2008 Terralec did have some big dichroics for parcan sizes at sensible prices -ask them (dot co dot uk). They were flat of course! Link to comment Share on other sites More sharing options...
rob_cheese Posted January 13, 2008 Author Share Posted January 13, 2008 The application I had in mind was for a blue wash on a cyc. (To create that bright summer's day - blue sky and fluffy white clouds with a gobo look). My problem with blue gels is that they absorb such a lot of light that I can't get such an intense colour as when doing something like red. Is the answer simply to use more lanterns and study the absorbtion spectra more carefully when choosing my gel? Rob Link to comment Share on other sites More sharing options...
gareth Posted January 13, 2008 Share Posted January 13, 2008 Dichroics aren't the answer. The reason a red cyc wash will look more intense than a blue one is that the 'white' light that you're filtering has more red in it than it does blue. It doesn't matter what colour medium you put in front of it - you can't put back what isn't there. Link to comment Share on other sites More sharing options...
musht Posted January 13, 2008 Share Posted January 13, 2008 Couple of catches with dichros, they are usually expensive, and a bigger gotcha on a flood light is they change colour with angle, blue is only blue dead in line with the lamp axis, as you move further off angle the light changes to magenta. Cheaper dichros are about but trying to get a batch all the same colour or ever replace a broken one with close match colour is difficult.Like wallpaper and LEDs, dichros are made in batches and the particular shade in any batch might be subtly different from the last. Link to comment Share on other sites More sharing options...
Bryson Posted January 14, 2008 Share Posted January 14, 2008 Also, Coda gelframes are curved when in use, so any kind of Dichroic replacement would have to be curved too. Many, many pennies. That, and the fact that due to the reasons stated by Musht and Gareth, A: Wouldn't work and B: wouldn't do what you want, even if they did work. Link to comment Share on other sites More sharing options...
LXbydesign Posted January 14, 2008 Share Posted January 14, 2008 Excatly as gareth said. Blue is blue. !! ** laughs out loud ** The gel has a lower transmission percentage than red hence why the light ouput is reduced. so to get a brighter "sky" u can do the following.. a: use a brighter blue with lower transmission b: use higher wattage foods c: add more units d: if your not already doing so , light the cyc Top AND Bottom!! Link to comment Share on other sites More sharing options...
LBLight Posted January 14, 2008 Share Posted January 14, 2008 Attention - Dichroics do not work on Cyclorama and Floodlight applications. It is the angle of the lighting beam that will determine the colour. - There was an experience I heard of when they set up Lion King in NY - The result is a rainbow, instead of only one colour. For longrun shows, you will need to put normal (colour) glass filters on cyc units to have an equal colour on the backdrop. I do agree that the dichroic colours in front of Par Cans etc. are more vibrant, but unfortunatly do not work in this case. In some of my work I could use my Wash Moving Lights pointed towards the CYC or bounced of a white floor, just in front of the cyc, to give the cyc more brilliance, but this depends on the stage set. Larry Link to comment Share on other sites More sharing options...
LXbydesign Posted January 14, 2008 Share Posted January 14, 2008 well for most west-end shows , thats what the chargehand LX would be doing during the day!! replacing colour!! woudnt shining moving wash's at a CYC give u an uneven coverage? sure , I ve done it if ive wanted a specific area washed or just a "colour- blobby-breakup-effect!!" but I would never use them for an even coverage. Link to comment Share on other sites More sharing options...
Nick S Posted January 14, 2008 Share Posted January 14, 2008 ...but if you've got enough money to hand to be considering dichorics, would LED battens not be a viable solution for you? Something like the Pixel range or a CK ColorBlaze? Blue LEDs can be far more vibrant on cycs than traditional incandescents. Link to comment Share on other sites More sharing options...
indyld Posted January 18, 2008 Share Posted January 18, 2008 Hi Rob, All the above reasons explained the reason why dichroics won't help. So we're back to choosing gels and lanterns. If you need more blue punch, see if you can find a light source with more blue in the output. If dimming them isn't a requirement then some kind of discharge source, maybe. A load of blue lamped MBI's (not exactly Sky Blue but barking bright), perhaps. Even it boils down to gelling Coda 4's let us know what colour you had in mind and we will probably be able to come up with a higher transmission alternative (warning: may turn into LD bickering, though). There have also been many discussions about the shortcomings of LED fixtures on this board. You might like to have a look through them before going down the LED route. Best wishes, Link to comment Share on other sites More sharing options...
LXbydesign Posted January 18, 2008 Share Posted January 18, 2008 In connection with indyds post , I would suggest you scroll up and re-read my first posting!! choosing a blue with a transmission of at least 15% will get u a nice tone - and not lose too much light make sure you get HT gel of course HTH Link to comment Share on other sites More sharing options...
andy_s Posted January 18, 2008 Share Posted January 18, 2008 how about using a skycloth rather than a white cyc? if it's already a bit blue to start with it might help ( this is inyld's suggestion of a blue source looked at from the other end.) speaking personally, I'd say dimmable sources were essential when lighting cycs or cloths. Link to comment Share on other sites More sharing options...
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