LED power - light comparison

[Richard CSL]

Ok I have been asked to quote to replace an old theatre install for LED. Now the customer has 40 par 56's pointing directly at the stage from 3 bars 5M 10m and 15m in front of the stage.

on stage there are another 16 par 56 at 300 watts each

 

Assuming for now that all the front of house lamps are 500 watt. this is pulling 20K and the on stage is pulling another 4.8K.

 

So the real question is how many led par cans should I use to replace these existing lights.

 

OK lets assume that with all this lot turned on the stage is firstly a hot house and secondly the brightness is probably overkill. Because let's assume you only use all those lanterns for colour changing so you can effectively divide the whole lot by 3 for the red Green and Blue content of the light.

 

So my other question is , what par can. So Thomann do a really cheapie for 33 euros but only goes up to DMX ch127. Not a problem because many cans will probably be on the same channels anyway to give enough light.

 

Should I use par 64 cans as there are more led's per unit, now the cost is up to 37 euros per piece or do I go for the long nose 122 euro per can unit. Should I also use some of the 6000K white units for infill, thereby not relying on the RGB units to produce a more normal light.

 

Any comments and advice greatly appreciated from those of you who have already done something like this.

[Brian]

What lamps have the P56s got in them?

 

It's important because LED units have beam angles which don't ideally match those of filament sources.

[Richard CSL]

What lamps have the P56s got in them?

 

It's important because LED units have beam angles which don't ideally match those of filament sources.

 

 

The par 56 on stage are only at a 9 foot height so I would imaging they are NSP. but there again they might be wide to illuminate any back cloth . When I was there thaere was no cloth but curtain rails are evident. I know the leds have a medium dispersion about 30 degrees so not a problem, they actually fall between NSP and WSP ranges .

[Guest lightnix]

As I've said before: I would not recommend using RGB LEDs as a front wash, due to the odd effects they can produce on coloured surfaces and fabrics.

[musht]

Reality check client has 56 cans installed with dimming and power for at least 25kW of light.

 

It will take an awful lot of €33 cans to reach same level of brightness, sure your aware of this , make sure your client is.

 

15m is too far for 5/10mm cans, much more expensive lites or a redesign of the rig, clients choice and expense.

 

RGB for anything `straight` won`t work well, 6000K is very blue attempting to warm it with gel will drop the output to below dismal.

 

If have to use some sort of halogen frontlight for some things , can the LEDs keep up?

[greenalien]

If you want to replace a PAR 56 with an LED fixture of comparable brightness, forget about the first-generation LED devices that use multiple 5mm or 10mm LEDs.

You need to be looking at something like this - 24 x 3W LED PAR and as you can see, they're an order of magnitude more expensive that the cheapest item you were considering. For a little more outlay, you could consider these, which also have a zoom facility. Despite the cost, and you're probably looking at needing 24 of these to replace what you currently have, they are still economically worthwhile over the long term, due to the saving in power and replacement lamp cost over the life of the luminaire. However, as others have pointed out, LEDs don't do warm white very well, so you may need to keep some of those old parcans and dimmers!

[ChrisBogg]

Look at something like the sgm palco over the stage and was it elation that did a LED fresnel for front of house on the closer bar. I would stay clear of LED sources for the further bars.

 

Chris

[MobileMikey]

Ive been using LEDs now for a couple of years on our mobile rig and they are fantastic for colour washes and they keep small drama groups more than happy but, IMO as soon as you bring up a profile from foh it kills the colour from them completely, well it does with mine anyway, they are 18*3w showtec led's that im using. Just my 1.5c, probably not worth 2!

 

 

Mick