musht Posted April 12, 2015 Posted April 12, 2015 http://www.sciencechannel.com/tv-shows/how-its-made/videos/led-stage-lights/
paulears Posted April 13, 2015 Posted April 13, 2015 Interesting - so what, exactly, makes these so amazingly expensive, considering the thing consists of a power supply, pcbs, some stick on mirrors and a single lens? Hardly precision engineering?
timsabre Posted April 13, 2015 Posted April 13, 2015 Interesting - so what, exactly, makes these so amazingly expensive, considering the thing consists of a power supply, pcbs, some stick on mirrors and a single lens? Hardly precision engineering? Market positioning... Being less cynical, the LEDs and drive electronics are quite expensive too, and there is a considerable R&D input to pay for.
paulears Posted April 13, 2015 Posted April 13, 2015 There didn't seem anything truly groundbreaking in it, did there? In fact almost identical to many of the cheaper LED products. The light engine seemed quite straight forward, and the collimator quite basic in the design.
timsabre Posted April 13, 2015 Posted April 13, 2015 There didn't seem anything truly groundbreaking in it, did there? In fact almost identical to many of the cheaper LED products. The light engine seemed quite straight forward, and the collimator quite basic in the design. The multiple colour light engine (7 colours of LED I think?) is quite different to what everyone else is doing, and the hexagonal beam thing does a very good job of producing evenly mixed colour, I bet they spent a good few hours getting that right.But at the end of the day, they are ETC with a premium product and presumably they can sell enough at that price tag.
Jevans Posted April 13, 2015 Posted April 13, 2015 There didn't seem anything truly groundbreaking in it, did there? In fact almost identical to many of the cheaper LED products. The light engine seemed quite straight forward, and the collimator quite basic in the design. And yet there must be something good about it or people wouldn't be paying for it. ;) They're much simpler than I was expecting too - when I fitted the cyc adaptors to a set of them I had a peer in and assumed the large metal tube was some sort of complex, clever sealed assembly with the engine and reflectors in: discovering that it's just a tube with some sticky mirrors in rather destroys that impression...
the kid Posted April 13, 2015 Posted April 13, 2015 Interesting - so what, exactly, makes these so amazingly expensive, considering the thing consists of a power supply, pcbs, some stick on mirrors and a single lens? Hardly precision engineering? Market positioning... Being less cynical, the LEDs and drive electronics are quite expensive too, and there is a considerable R&D input to pay for. I believe the colour balance is in that as well. There is a reason why each unit will look the same on the floor but one might have a touch of another colour etc.
bigclive Posted April 13, 2015 Posted April 13, 2015 It may look simple, but I bet that took a lot of research and development to get perfect. I like the way the large array of LEDs is mixed by using a kaleidoscopic tube to basically create a mass of overlaid images of the LEDs. I'd like to see one with a lens just banging out the kaleidoscope effect on its own. I've not seen the output from the finished unit (yet) but given its pedigree I would think that it will be good. Sadly the design is so outwardly simple looking that it's going to get ripped off rotten by the Chinese manufacturers, who will invariably just bang in arrays of the cheapest LEDs they can find. Original = colour matched and calibratable. Chinese copy = totally random shades between fixtures. (But fine for disko use.)
Jevans Posted April 13, 2015 Posted April 13, 2015 I'd like to see one with a lens just banging out the kaleidoscope effect on its own. Interestingly, if you look at the end of one when it's got a profile lens on, you can actually see the individual LED blobs of light showing even at the end of the main lens, so it's not totally collimated by the time it leaves the fixture, though it is at any reasonable throw distance of course. On the other hand when you put a cyc adaptor on it's mixed right from the exit of the adaptor (the cyc adaptor is a very clever bit of optics in it's own right.) I'll be interested to see what the new fresnel adaptor looks like...
DrV Posted April 13, 2015 Posted April 13, 2015 Have a look down the business end of a Selecon PL/Profile or Fresnel without the lens in place. Looks as though there are dozens of LEDs. In fact there are 4!
David Buffham Posted April 14, 2015 Posted April 14, 2015 I've been using a number of these fixtures for a few months, and they are very good. The output is bright - both in pastel and saturated colours - and is of consistent quality. The fades to and from black are extremely smooth for LEDs, and the fixture has modes that emulates tungsten dimming performance and colour shift. These are definitely quality fixtures. As I understand it, each fixture is calibrated in the factory such that the as-built characteristics of each colour group is updated back into the fixture - so if a console sets the colour through HSI control, the fixture does the maths to determine the output level of each colour and adjusts as necessary to compensate for any colour variance in that particular fixture. So in theory fixtures bought at different times should all have identical output when set to the same point in the HSI world. Also I know that ETC are doing a lot of work on colour control, both on the fixture and console sides. e.g. Eos 2.3 will start to introduce more advanced colour control tools, including the ability to set the fade path between two colours. e.g. crossfade between two colours can be set to simulate the effect of a cross-fade between two tungsten source 4s in those colours - e.g. you can directly get from blue to amber without going through purple, or programming additional follow-on cues. The photo in this link shows the 7 colours in the LED array: Link
timsabre Posted April 14, 2015 Posted April 14, 2015 So in theory fixtures bought at different times should all have identical output when set to the same point in the HSI world. No, they do this because the LEDs themselves can be quite variable in output (unless you pay a lot of extra money to have them sorted to be identical), so the calibration allows them to use cheaper LEDs and still ship the fixtures with identical output. The LED output reduces considerably with age / usage, so an old fixture will not give the same results as a new one even though they both left the factory fully calibrated to be the same. I believe you can recalibrate them to fix this but I am not sure how that works without complicated test gear.
the kid Posted April 14, 2015 Posted April 14, 2015 I was under the impression that they had a brain that understood run hours each "pixel" had done and adjusted (over drive) up to a limit.
timsabre Posted April 14, 2015 Posted April 14, 2015 I was under the impression that they had a brain that understood run hours each "pixel" had done and adjusted (over drive) up to a limit. Are you sure, I don't think that the aging changes in LED are predictable enough for that to work
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