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[Alex Thompson]

Is there a general rule of thumb for LED power required to equal the brightness of a par 46,56 or 64 light?  I would like to go with RGBAW but may settle for RGBA or RGBW.

I want to upgrade my old PAR46 rig to 8 x LED pars and would like to be close to the same brightness as 8 x incandescent Par 64's.

[Randall Hyde]

Is there a general rule of thumb for LED power required to equal the brightness of a par 46,56 or 64 light?  I would like to go with RGBAW but may settle for RGBA or RGBW.

I want to upgrade my old PAR46 rig to 8 x LED pars and would like to be close to the same brightness as 8 x incandescent Par 64's.

The Blizzard Rocklite RGBAW fixtures come close (and at a decent price, under $400 each), particularly when you consider the light lost when you put gels on the PAR64 cans. A bare incandescent will blow away the Rocklite (something like 45,000 lux versus 25,000), but colored gels cause a 75-99% loss of light (depending on the gel, saturated ones tend to absorb more) so the RL RGBAW does a good job next to an incandescent.

Couple of tough issues with the Rocklite:
1) Discrete LEDS (R, G, B, A, and W) so they don't work as well on the back truss (where the audience can see them) as they do on side or downstage (front) trusses.
2) Getting hit in the face with their light is about like looking into a laser pointer -- very uncomfortable at full brightness. Incandescents are much nicer (though largely this is due to the diminished brightness after passing through a gel, there is also the issue that the LEDS are largely monochromatic so you're getting a huge amount of light at one frequency rather than having it spread across the spectrum [which is easier on the eyes, I suppose]).
3) Fan is a bit loud; not an issue for loud concerts, but could be an issue in quiet theater settings or HOWs.

I've had real good luck with the Rocklite RGBAW units (not as good luck with some other Blizzard units, such as the Fab 5). If you can live with the size (which you should be able to if you're replacing PAR64 fixtures) it's not a bad choice.

Blizzard also makes a Rocklite AW unit (just white/amber). I've got four of these. Slightly pinkish, but if you just need warm white on the stage they're about $100 cheaper than the RL RGBAW units. Still, I'd recommend going with the RL RGBAW units as they're more flexible.

I suspect that other LED brands that come close to matching the light output of the PAR64 will be significantly more expensive. There are some cheap Chinese brands out there, but I like having a manufacturer in the US whom I can send bad fixtures to (Blizzard's units are made on the same lines as those cheap Chinese units, so the quality isn't much higher, but when something goes wrong it's much easier to deal with Blizzard than someone in Taipei who doesn't speak English).
Cheers,
Randy Hyde

[Alex Thompson]

The Blizzard Rocklite RGBAW fixtures come close (and at a decent price, under $400 each), particularly when you consider the light lost when you put gels on the PAR64 cans. A bare incandescent will blow away the Rocklite (something like 45,000 lux versus 25,000), but colored gels cause a 75-99% loss of light (depending on the gel, saturated ones tend to absorb more) so the RL RGBAW does a good job next to an incandescent.

Sounds like about 20% LED watts vs. Incandescent of course depending on mfg and color.

[Randall Hyde]

Sounds like about 20% LED watts vs. Incandescent of course depending on mfg and color.

Assuming only one saturated color (R, G, B, A, or W) of course (though the 20% isn't exactly correct as each color puts out a different maximum amount of light). Of course, if you're producing a color by mixing colors (using additive color mixing) you get more.

Ultimately, I like the warmer/broader spectrum produced by incandescents.
Power budget and heat have cause me to switch to LEDs.
I run 16 Rocklite RGBAW fixtures on the sides of the stage and they *really* light things up (can't run them on the front truss as they are too bright to put into the performer's faces; I run Fab 5 fixtures there as they are about half the lux of the RL RGBAW and are useful for throwing some amber on the performer's faces and white/amber onto the lead performer).

The Fab 5 Pucks would be great fixtures (especially at $200 each on the street) if they were a little more reliable.
Cheers,
Randy Hyde

[Josh Daws]

the saying that you can't put the blizzard fixture out the front is true and inaccurate at the same time...lol my reason for this is that this is the case with EVERY fixture. ANY light below a 30degree angle (to the area to be lit) will be bright in eyes.

so my point is that using that analogy of "you cant put this LED light out front cos its bright" shouldn't be used as this is the case with ANY light shining in eyes. ok...my bitch session is over...

to respond to the OP, whether you decide RGB, RGBA, RGBAW, VW, or whatever (this has NOTHING to do with intensity), you need to be able to research it, then physically see it. regardless if i recommend something, or it someone else. the importance isn't necessarily HOW BRIGHT per say, but more a mixture of things. you want to firstly look at is throw distance, second is coverage, and thirdly how bright it is. the last thing that you want is a tight beams angle and bright and you plan to use them side stage. the coverage will be horrible. buying (for example) 8 lights to do what 4 lights could do. not to mention that your money could be better spent on something else.

to specifically answer your question, personally i don't think there is an equation to work this out as there are many factors to consider for example, how many LED's, beam angle, wattage of each LED, manufacturer etc. i have seen many LED fixture match that of a 300w Par56, PAR20, 575w Profile. the performance and last ability will generally depend on how much $$$ you want to drop.

i hope this helps.

[ProSoundWeb Community]