How bright should LEDs be?

[carsonld]

I am looking at getting some LED fixtures but had some questions on how to figure out if they will be bright enough. The LED will be competing with a source four family that has 575w in them at varying heights. I know that I am look at the lux and how bright they are at a certain distance but how do I know how bright the lux is? And if the wattage is higher is it brighter?

 

[Dionysus]

You can compare the numbers more or less directly. The ETC website has lux/fc measurements on the various Source-4 fixtures with various barrels. http://www.etcconnect.com/minisite/sourcefour/metrics.html
The numerical comparison will help you figure out what you can hope to expect from the fixtures more or less. Remember that "brightness" measured in lux or foot candles may not entirely account for how the eye would comparitivly precieve the light in all situations especially when you are talking about gel etc.

 

[JD]

Rule of thumb:
On white and light colors, the S4's will blow the LEDs away.
On super deep colors (such as deep blue) the LEDs will blow the S4s away.
This is because gels on a S4 is "subtractive" color in that you start with white and take away the colors you are not using. To get a deep color you may be passing less than 1% of the light. Conversely, LEDs are an "Additive" color mix in that you start with RGB (and sometimes AW) and add their output to get to white. So basically, deep blue would just be driving the blue LEDs at full throttle and may represent 20 to 30% of the fixture's output.

 

[gafftaper]

The best thing to do is call your dealer and ask for a demo. Without seeing the fixture in real life under the actual conditions of your theater it's very hard to judge if it will be bright enough. Consider the wide variety of LED products that Chauvet makes, every model is a little different. Even with all the data they provide, it's hard to tell which fixture is going to do the job. Now switch to a cheaper product line like Blizzard or similar "high end Chinese" fixtures. You will find even less documentation on their products.

If you need help with getting a demo let us know.

 

[adamcarl69]

On super deep colors (such as deep blue) the LEDs will blow the S4s away. good

 

[BillConnerFASTC]

I'd generally say, as bright as you can afford, after you've eliminated the ones that don't dim well and after you've eliminated those that don't do "white" well enough for the application. The shoot out in your space is best answer - side by side. We find even the look of some fixtures - the multi-colored lens end and spill - affects the decision. ETC emphasizes great white. Phillips does good white and a bit more color. Altman's white is acceptable but their "red" or "blue" makes ETCs pale by comparison. Prisms are well known gor brightness and very consisten color over time, but slso ecpendive, big, heavy (may have improved - im due for an update), and not as much lower wattage. And that was all of a month or two ago - it seems to always be changing.

A quartz shootout was pretty easy by comparison.

 

[gafftaper]

@BillConnerASTC plus, a quartz shoot out required you to line up ETC, Altman, and Strand side by side. With the endless list of Chinese made products, there are hundreds, if not thousands, of fixtures out there that claim to do the job.

Thus I go back to call your local dealer and see what they sell and what they can get you for a shoot out. It may not be the dream list, but it's impossible to see everything these days.

 

[BillConnerFASTC]

@BillConnerASTC plus, a quartz shoot out required you to line up ETC, Altman, and Strand side by side. With the endless list of Chinese made products, there are hundreds, if not thousands, of fixtures out there that claim to do the job.

Thus I go back to call your local dealer and see what they sell and what they can get you for a shoot out. It may not be the dream list, but it's impossible to see everything these days.

And Colortran for a while. Yes, but I just tend to stick to major manufacturers - probably should put Chauvet in there. I understand there is a market for the mo-nsme imports but I'm not in that market.

Bill