By Charlie Davidson
Earlier this week Barbizon Electric in New York put together a thorough and informative side by side comparison of leading LED fixtures. All were ellipsoidal spotlights and while this test may have less immediate interest to FDTimes readers than a test of Fresnel or panel type LED fixtures, the wide variation in design and performance points to the confusion in the marketplace and the difficulty that crews and rental companies have in selecting equipment.
Elipsoidal spotlights (often simply known by ETC’s trade name, Source Four) commonly used in theaters have grown from a specialty light to widely used fixture in TV studios. Their long throw, even field and sharp shutter ability make them ideal in these environments. While feature or commercial DPs may only use Ellipsoidals in special situations like product shots or for pattern projection, the issues of color, output and cost present challenges to anyone looking to use or purchase any type of LED fixture.
We saw 29 fixtures from 11 manufacturers grouped into four categories, Tungsten, Daylight, RGB and bi-color (or “Tunable White”). Barbizon showed us performance in terms of output, color temperature, CRI and dimming curve and what will perplex those who must choose which fixture to rent or purchase is that there was no clearly superior fixture.
The test pointed out the compromises manufacturers make in designing LED fixtures and the difficulty in selecting one for a job. One fixture might have better color rendering but lacked output while another had great color and output but a less than desirable dimming curve. Look at the range of performance in Barbizon’s test results.
- Price: $895 – $3,600
- Color Temp at Tungsten Setting: 3041 – 3370oK
- Color Temp at Daylight Setting: 4670 – 9013oK
- CRI 70 – 93
- Output at 10 feet: 93 – 812 fc (1001 – 8742 lux)
Seeing this group of fixtures projected side by side was even more revealing than the numbers alone. At their pre-set tungsten settings, few bore any resemblance to the 575W ETC Source Four reference in terms of color or color quality and no two were alike. According to John Gebbie, who organized the demo, TV Lighting Directors had two differing responses to the disparity. Some felt that they could live with any of the fixtures as long as the CRI was high enough to properly render colors and that they would simply white balance to the given light. Others felt they required the “Tuneable White” feature, which provides the ability to adjust color temperature within a limited range.
We come from a time where a limited number of manufacturers produced reasonably similar fixtures. One might debate the attributes of an Arri or Mole 2K Fresnel but a 2K Fresnel was a known quantity. In what appears to be a headlong rush to embrace LEDs we are losing these common reference points and the confidence that there will be consistency from fixtures of a given type. All of which calls for more time for testing. The Barbizon demo was a good place to start and we look forward to a similar test for LED Fresnels and Panels.