LED floodlight

[u_dakka]

My boss at work mentioned the idea of having a LED floodlight for this opening scene where we are having 3 prisms sillohetted. Possibly having them yellow in colour to symbolise morning. I like the idea of going for LED, low current usage, quicker than halogens on fades, cooler - there are many advantages. However I haven't used them before and I was wondering if there were any pitfalls to be aware of? Do they have a shorter throw? Is it a narrower beam? Is there anything electrical that I've missed? Are they easy to find hire companies to hire in, and what would be considerably more expensive than ordinary halogens for hiring (ie more than twice the cost)?

 

andy

[pritch]

There've been a couple of threads about this, mainly about parcans.

 

The most interesting of the threads (in my opinion) is this one:

http://www.blue-room.org.uk/index.php?showtopic=18034

[u_dakka]

I've read that one and found it interesting, thanks. However I have no idea about Lux in real terms, I have no idea what an ordinary halogen flood provides, and I know halogens appear wamer and more yellow - but LED's I presume would end up more white. am I right? and my original questions still stands

 

andy

[Tom Baldwin]

Cost: they can be much more expensive to hire.

10 out of 10 hire the Par56 LED parcans discussed extensively on this forum for about twice the price of a parcan. But the LED brightness is less than a Par56 can, especially in a relatively unsaturated colour such as yellow.

To hire a PixelPar90 (which is much, much punchier) will take you towards £100 each.

 

Beam angle: do you really want a flood? LED fixtures tend to be quite narrow, unless you add some form of diffusion.

 

Colour temperature: odd question in this context: you gel a tungsten fixture to get the colour you want, with an LED fixture you adjust the output levels of red, green and blue LEDs to get the colour you want. In principle, you can get the same colour out of both. In practice, LED generated colours won't always look quite the same as a tungsten generated colour - especially so for less saturated colours.

 

Desk: if you only want one colour fading in and out, then the choice of desk doesn't really make much odds. If you want to do lots of colour mixing, you'll be happier with a desk with LTP channels.

 

Practical: more cables running across stage (assuming you're lighting these prisms from the floor?), as you've got DMX and power.

 

Cheap fixtures can suffer from problems flickering while dimming - things like PixelPars or Palcos don't.

 

 

 

Electrical: you need a source of hard power, rather than a dimmer circuit. However, nothing that you could hire takes massive amounts of power, so as long as you have a 13A socket handy, you'll be fine.

[Ekij]

having a LED floodlight having 3 prisms sillohetted, yellow in colour.

The point of a prisim is generally to split the light into the rainbow.

A broad spectrum light that is biased towards yellow will still do this.

An LED fixture producing yellow will be only two fairly tight frequencies one Red, the other Green which will not work well through a prisim.

[u_dakka]

we're planning on running them out of a single 15A socket which is dimmable from the dimming racks controlled by a desk. and the idea is similar to this (seen from audience) from what ive got from the idea the director gave me. figured a flood would give a best result considering there are three prisms about 5' tall, about 7' away. and they want it all lit from a single point.

the LED light was merely mentioned cause we have hardly any overhead on the dimmers, and so dont want to draw to much current, and its probably that the director doesnt want the entrance/exit blocked by a light on a vertical stand.

 

andy

 

PS the prism refers to the shape of the wooden structures on wheels rather than it being made of glass.

[tom_the_LD]

Electrical: you need a source of hard power, rather than a dimmer circuit.

 

we're planning on running them out of a single 15A socket which is dimmable from the dimming racks controlled by a desk.

 

 

 

I feel these posts may contradict slightly?

 

 

EDIT: Trying to get quoting to work properly

[five_pin_xlr]

These fixtures can be run via soca or lectriflex, just dont plug them into the dimmers.

All DMX attributes should be controlled via the desk, with the fixtures having there own non-dimmerable supply.

 

LED floodlight wise, Thomas Pixel Pars are good and so is PULSAR Chroma Flood, be careful on which angle you get.

 

hth

[Tom Baldwin]

OK, having seen that picture:

 

1kW flood, no question.

You'd need a Palco to do that in LED, and they are much more than twice the price of a 1kW flood.

 

Also, the sun tends not to snap in and out - a fade would feel more natural.

 

Power: the effect shown works best with maximum contrast between front and back, i.e. you want hardly anything else turned on when this is happening. That being the case, power consumption isn't an issue.

 

Space: a 1kW groundrow flood won't take appreciably more space than a Palco - check the datasheets - and both have built in floor stand arrangements, ergo there's no physical difference between the two as far as the director is concerned.

 

One other comment, almost every LED fixture uses multiple LEDs to achieve the required brightness; this means the audience might perceive the source as being multiple dots, rather than a single source.

 

Finally, consider also a CP95 lamp in a short nose parcan. A little harder to source (many hire companies don't have them), but it's a round source, rather than the distinctly linear shape of a 1kW flood.

[Pete]

Finally, consider also a CP95 lamp in a short nose parcan. A little harder to source (many hire companies don't have them), but it's a round source, rather than the distinctly linear shape of a 1kW flood.

 

The big boys should all have them,CP95s are a good secret weapon in any LDs inventory.

 

Pete

[u_dakka]

Does this mean you think I'll be better with a 1kW halogen flood rather than a LED one? The LED one was just an idea that my boss was floating around. out of interest are LED floods only available in RGB or can they be as a natural one colour eg white?

hope that makes sense

andy

[Tom Baldwin]

Yes, I think you'll be better off with a halogen flood.

 

I can't see a benefit in this application for LED technology.

 

More LED fixtures (at least in the theatrical market) are colour mixing than not, but there are some single colour products available. I thought there was a white LED version of the PixelPar, but I can't find it on their website just now. Also, Pulsar will do custom versions of their products in single colour LED, ISTR.

[niclights]

Unless you must have low heat/power/high IP rating then as said it's probably going to be uneconomic. If you are going to use LED then only realistic solutions are SGM Palco3 or DTS Delta RGB. Both have lens options for flood width.

 

The main problems I have found with using these are the initial on value. It is currently impossible to get an absolute perfect fade - they always snap on, albeit at a low but perceivable value. This may or may not be a problem for you depending on operation. Another problem is many use separate red, green and blue LED's which can give strange shadows/cause problems at close range and look terrible off-axis especially yellow (ie. red & green!) The Delta RGB's use multi-colour LED's which overcomes these issues and is one of the reasons I chose them over Palco's. Generally I have found these units are good at producing most colours - warm and cold and even do a very nice CTO. You can also get them in only white. You'll never get as good as real tungsten though.

[Jivemaster]

Currently LEDs are 5x the price of a conventional lamp and less than a fifth of the light output. Fantastic for lamp life though this may not matter in a typical theatrical season. The fabulous effects comilg from clever control of LEDs are great but you dont need them here. SO - conventionals would be my starting point. ( unless of course the Director finds LEDs to be a "continuing employment" type concern)!

[Graham Threader]

I have to take Jivemaster to task when he asserts that LEDs output is only a fifth of a conventional filament lamp. He must have been viewing the spec sheet upside down. Light output of LED fixtures is several times that of an equivalent power in a filament lamp.

 

The Palco (130w) with a 25 degree collimator lens set has a light output and beam angle roughly equivalent to that of a PAR64 fitted with a CP62 (1000w). This gives an efficiency gain of 7 times. Not all LEDs perform as well as Palcos or JTE products, but then you get what you pay for.

 

From the cost perspective there is no doubt that conventionals would be much cheaper. It is always worth looking at the cost of an effect/scene with a view to avoiding using too much of the overall budget, to the detriment of the rest of the performance.