timsabre Posted January 10, 2018 Share Posted January 10, 2018 The Chauvet works by having a metal plate behind the dome lens with a circular apeture. The lens system then focuses on this apeture - poorly, but rather well for our purposes. If you take the lens off and move it to a closer distance you will get an image of the chip. At the proper distance we get the sharp image of the aperture and the even beam spread which is the blurred image of the chip behind it. Marrying the two systems (the two lights) may be too much of a challenge. Still it's all learning curves here and I have a month to get something that works. http://www.blue-room.org.uk/public/style_emoticons/default/wink.gif Interesting, doesn't that waste a whole load of light on the back of the plate though? Link to comment Share on other sites More sharing options...
kgallen Posted January 10, 2018 Share Posted January 10, 2018 You able to hold another lens element in front of the lamp and see what you get? Would have to be 4"+. Kind of depends on if you have one lying around. Ummm.... ok.... kinda... you've clearly got some interesting and fairly specific requirements with what you're doing. I guess I could pull a fresnel or PC lens out of a Prelude or use a Source 4 lens (26/36/50) lens. But what am I targetting and what am I looking for in the results? Happy to help if I can but realistically this would have to wait until mid/late next week as I'm in the middle of a production run at the moment and this kit is up in the rig... Regards,Kevin Link to comment Share on other sites More sharing options...
Karel Bata Posted January 10, 2018 Author Share Posted January 10, 2018 Tim, Looking at LEDs on eBay it does seem unusual. It's rather like a follow-spot with a hard edge - you're focussing on the iris and the light is out of focus behind. I would guess there's light loss, but it's a damn good little light! I suppose the dome lens in the Event Spot would be attached to the PCB in some difficult-to-remove way... Damn Kevin,No rush. I need to take a break form this anyhows! http://www.blue-room.org.uk/public/style_emoticons/default/laugh.gif Yes, a very specific requirement. In fact it involves one lamp being gelled blue, and another red to create a 3D effect, so it occurs to me (somewhat belatedly! http://www.blue-room.org.uk/public/style_emoticons/default/huh.gif) that instead of gelling them up I could maybe just swap out the current white chips for red and blue ones and gain an immediate tripling in intensity! And then maybe go from 3W to 5W while upgrading the power supplies. I'm sure the housing could take that and it would yield a five-fold increase overall... Maybe that's the easiest thing to do. I'll contact Chauvet and see what they say. Link to comment Share on other sites More sharing options...
Stuart91 Posted January 10, 2018 Share Posted January 10, 2018 In fact it involves one lamp being gelled blue, and another red to create a 3D effect, so it occurs to me (somewhat belatedly! http://www.blue-room.org.uk/public/style_emoticons/default/huh.gif) that instead of gelling them up I could maybe just swap out the current white chips for red and blue ones and gain an immediate tripling in intensity! Unlike a traditional tungsten source, white LEDs emit quite a narrow range of hues, so gelling them up to a primary red or blue will massively decrease the intensity. Definitely worth trying blue and red chips - it sounds like that will yield a large improvement. Link to comment Share on other sites More sharing options...
Karel Bata Posted January 10, 2018 Author Share Posted January 10, 2018 Ah yes, of course. I had noticed they were dimmer when gelled up than expected. Thank you. This must play havoc with traditional lighting design! Link to comment Share on other sites More sharing options...
musht Posted January 11, 2018 Share Posted January 11, 2018 LED specific gels are now a thing, because of way a white LED generates white https://www.digikey.co.uk/en/articles/techzone/2013/apr/defining-the-color-characteristics-of-white-leds Coloured LEDs are almost monchromatic Link to comment Share on other sites More sharing options...
timsabre Posted January 11, 2018 Share Posted January 11, 2018 Great diagram!Even using the LED-specific gels can result in unexpected effects when lighting coloured objects, due to the output spectrum of the LED. Definitely not the same as the equivalent gel on a tungsten lamp. Link to comment Share on other sites More sharing options...
sunray Posted January 11, 2018 Share Posted January 11, 2018 I knew white LED had a restricted spectrum but I am surprised just how limited it is. I find the fluo spectrum very confusing (but not doubting) as it is used in colour matching locations. Link to comment Share on other sites More sharing options...
timsabre Posted January 11, 2018 Share Posted January 11, 2018 I find the fluo spectrum very confusing (but not doubting) as it is used in colour matching locations. Yes I think the fluorescent diagram is suffering from the size of the green and red spike causing all the rest of the colour to be scaled down. It really looks more like the warm white LED one, but with a massive spike in the green and red. Link to comment Share on other sites More sharing options...
sunray Posted January 11, 2018 Share Posted January 11, 2018 Having said that there is, or possibly used to be, a fairly wide selection of flou colours. I recall northwhite being used in the print industry. Link to comment Share on other sites More sharing options...
timsabre Posted January 11, 2018 Share Posted January 11, 2018 This is probably a better rendering of fluorescent - these are halophosphor/triphosphor which are used when colour rendering is important. I presume your eye just ignores the big spikes as they are such a narrow band. http://www.lamptech.co.uk/Images/Illustrations/FL%20Spectra%20Halophosphor.jpg Link to comment Share on other sites More sharing options...
sunray Posted January 11, 2018 Share Posted January 11, 2018 Warm and daylight make a lot of sense, I'm still a bit surprised about cool though.I tend to agree with you about the big spikes, differentiate the curve and they get swamped.They may possibly start showing if a gel is used, I noticed that effect when I tried gels on cool white LED flood lamps. Link to comment Share on other sites More sharing options...
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