Does luminous efficacy matter in stage lighting? It should and it does for us at Elation!

If you’re still focusing on a lighting fixture’s wattage to gauge brightness, you’re missing the point. We’re used to thinking ‘the more watts, the brighter the fixture’ but with today’s highly efficient LED engines the rules have changed.

Fixture wattage is only half the story. Watts is a measurement of energy use, not brightness, and the total power draw of a lighting fixture doesn’t always equate to it being brighter. Two lighting fixtures may have the same wattage going in but have very different lumens measurements coming out.

Luminous efficacy, or lumen output per watt, is what’s important. A 250 watt LED engine that outputs 10000 lumens is twice as efficient as a 500 watt luminaire that outputs the same. A more efficient light source can add up to significant savings in energy and money.

There are a lot of factors that go into realizing the output performance of any lighting fixture – but it’s especially true with stage lighting fixtures. Pars, battens, floods, even moving lights often use multiple sets of optics. The quality of the optics, the overall optical design, even electronics like power supplies and LED drivers, can all significantly affect output.

Now while efficacy relates to total lumens / watt – that doesn’t always translate or give the full picture when it comes to stage lighting. Maximum beam candela can often be more important when you are painting air with light vs. lighting a stage or scenery. Example – a “beam” fixture can have a very low total lumen output because the beam angle is around 2-3 degrees – but the center beam candela can be very high and give a very effective result when moving beams across an arena. Example – when you see a show with 1200W lamp/ 25k lumen fixtures and an 189w lamp / 9000 lumen Beam fixture holds its own on the same stage with 21k lux for the 1200W and 40k lux for the 189W in the center beam.

Elation strives to be a market leader when it comes to luminous efficacy and has some of the most highly efficient LED engines on the market. For Example, our WW Profile HP fixture has a max total lumens of 10,075 lumens at 151W  with a peak candela of 48,536lux using a 50 deg lens.  This produces a light efficacy of 67 lumens / watt. Compared to a brand x competitor unit has a max total lumens of 9,607 lumens at 212W with a peak candela of 30,663lux using a 50 deg lens which produces a light efficacy of 46 lumens/ watt.

So…when you read a headline that a fixture has a 180W LED or 230W LED engine that’s great but it doesn’t mean the higher wattage one is brighter or certainly not more efficient. Moral of the story, if you are going to read spec sheets – ask for an IES file from the manuf. Which is the closest standard to compare true performance – best is always to get a product demo and bring your own light meter as your own eyes is often the best judge of light quality and efficacy!