being slightly north of the blackbody curve at about 0.42, 0.39 on a CIE 1931 diagram. This may be within experimental error, but a pushbutton correction of 0.8 minus green (adjustable in steps of 0.01) corrects the problem and
2700K and 6500K. The mired shift between selected and measured colour temperature was always below 10, with the least-good results at low 10% intensity settings. For reference, Lee one-eighth CT straw gel represents a mired shift of 18. These are great results; the Titan is up there with the very best LEDs, and certainly much better than an ageing HMI. GEL ACCURACY Lee and Rosco gels are simulated as they would behave on tungsten or daylight sources. We can assess the technical gels for accuracy, such as Lee’s No. 201 gel, full CT blue, to convert 3200K light to 5700K. With Lee Tungsten and the 201 gel selected, the Titan measured 5459K, a barely-visible error of -7.75 micro-reciprocal degree. With Lee Daylight and the 204 full CT orange gel selected, output measures 2915K, suggesting that the tube is simulating the virtual daylight source behind the gel as around 5500 or 5600K. White output leans fractionally towards greenish-yellow at 3200K,
demonstrates that the Titan could easily be matched to any reasonable white light source. At 5400K that tiny error disappears and the Titan lands right on the curve. FLICKER The CV600 meter fails the Titan on flicker, possibly because a form of pulse-width modulation is used to control the LEDs. Astera is careful to state that a randomly-scattered PWM algorithm is used to offset the flicker typical of naïve PWM found in lighting intended for live events. The random scattering is a very valid technique and test shots made of the Titan at 960fps, using a rolling-shutter camera, did not show any obvious problems. It’s hard to say if the Titan will be flicker-free under absolutely
all circumstances, but it’s difficult to show the fault if there is one. The Titan is hugely flexible and operates to a very high standard of colorimetry. A price of €580 is ambitious compared to the LED tubes often used to replace fluorescents, so it’s unlikely to become an automatic choice for every retrofit. Still, on a gameshow set the application is obvious, and it’s easy to see a drama taking a handful of them for special effects or simply as a conventional white light – because here, we have something that will do both.
ABOVE The unit is configured in 16 separate segments, each with red, green and blue plus mint and amber.
OCTOBER 20 1 8 | DEF I N I T ION 71
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