Chauvet Legend 412 User Manual download pdf

66 • January 2012 •

Lighting&Sound

America

TECHNICAL FOCUS: PRODUCT IN DEPTH

It’s been a little while since we looked at something from

Chauvet, an interesting manufacturer with a large range of

lower-priced products primarily designed for the nightclub

and similar markets. In recent times, Chauvet has intro-

duced an increasing number of more sophisticated prod-

ucts, clearly aimed at transitioning the company towards

loftier goals. The Legend 412 falls in that latter category; to

my mind, it undoubtedly has applications across many dif-

ferent areas of our business, and it will be interesting to see

how it competes with similar products. It joins the recent

trend of manufacturers producing very small LED-based

luminaires that, although possible to use as singletons, are

really designed for arrays of larger numbers. In fact, the tiny

size of the packaging fooled me when it arrived at my work-

shop. I saw UPS draw up, and opened the large doors,

ready for them to wheel in a road case or dolly; instead, the

driver stepped out of the truck and passed over this small

package with one hand. That makes a change!

The Legend 412 is a compact RGBW LED wash light

with some design features meant to facilitate its use in

pixel-mapped applications as well as more conventional

wash light situations. How does it stand up against a num-

ber of similar products on the market? I hope this review will

help you make that decision. I will follow my normal proce-

dure of following the luminaire from source to output meas-

uring, reporting everything as objectively as possible. All

results were based on measurements from a single unit sent

to me by Chauvet as typical (Figure 1).

All tests were run with the fixture operating on a nominal

115V 60Hz supply. However, the Legend 412 allows opera-

tion on supplies rated between 100-240 VAC, 50/60Hz, with

automatic voltage selection through a switched mode

power supply.

Light source

The Legend 412 uses 12 Cree XLamp MC-E 4 LED pack-

ages. Each contains four dies, one each of red, green, blue,

and white, mounted together closely under a single primary

optic. Figure 2 shows one of the 12 packages, with the

phosphor on the white LED clearly visible. The packages are

mounted on a single circuit board, which, in turn, is

attached to a finned aluminum heat sink. Figure 3 shows the

complete circular array.

Each four-color LED package has an associated second-

ary optic, to collate the beam down from its native field

angle of around 140°. The secondary optics are large TIR

(total internal reflection) lenses, where the LED fits within a

central base cavity at the bottom of the conical molded

plastic lens. Figures 4 and 5 show the array of TIR optics

and the detail of a single unit. Chauvet states that it runs the

dies at 700mA each, thus taking the Cree specification

sheet data for forward voltage; this equates to around 110W

for the total array.

The spectrum produced by all emitters running at full

power is shown in Figure 6. As expected, this is dominat-

ed by the three peaks from the red, green, and blue emit-

ters, with the subsidiary blue and yellow peaks from the

white emitters helping fill in the gaps in the cyan and

amber areas. Figure 7 shows the white on its own, to the

same scale, so you can see its contribution to the whole.

Its output is very broad across a lot of the spectrum, so it

appears much brighter to the eye than the low peak level

might suggest. It’s the area under the spectral curve that

represents energy, and thus total brightness, not the height

of the peaks. The addition of white really helps with the

color rendering of such a system, particularly if the units

are to be used on skin tones (although I suspect that won’t

be a normal application for the Legend 412). Those cyan

and magenta regions are critical to the human eye’s evalu-

ation of flesh tones.

Good cooling is essential for LED longevity and consis-

tency. As mentioned above, the LEDs in the Legend 412 are

mounted in contact with a finned aluminum heat sink,

The Chauvet Legend 412

By: Mike Wood

Figure 1: Fixture as tested

Lighting&Sound

America January 2012 http://www.lightingandsoundamerica.com/LSA.html

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Summary of Contents

Page 1 - The Chauvet Legend 412

66 • January 2012 • Lighting&SoundAmericaTECHNICAL FOCUS: PRODUCT IN DEPTHIt’s been a little while since we looked at something fromChauvet, an in

Page 2 - Optics and output

www.lightingandsoundamerica.com • January 2012 • 67which, in turn, is cooled by a single axial fan. Figure 8shows the arrangement, with the fan coolin

Page 3 - 0[HSSHKKZ\W!

68 • January 2012 • Lighting&SoundAmericaPRODUCT IN DEPTHquite good. I found some issues when using red and greenonly: The mixed yellow output was

Page 4 - Thea Awards Gala

www.lightingandsoundamerica.com • January 2012 • 69dims down—particularly at the bottom end—but Chauvetavoids that issue well in the Legend 412.I meas

Page 5 - TOUCH The Future

70 • January 2012 • Lighting&SoundAmericaTECHNICAL FOCUS: PRODUCT IN DEPTHthe same solar cell and oscilloscope setup used for meas-uring PWM) of 0

Page 6 - 815.899.9888

Pan and tiltThe Legend 412 has a pan range of630° and a slightly restricted tilt rangeof 200°. Movements were quick, tak-ing advantage of the unit’s s

Page 7 - .dfd.com

72 • January 2012 • Lighting&SoundAmericaTECHNICAL FOCUS: PRODUCT IN DEPTHElectrical parameters and homing/initialization timePOWER CONSUMPTION AT

Page 8 - Conclusions

board and motor control drivers, aswell as the power supply and menusystem. Getting into the unit wasstraightforward. The external coverscome off the