Without question, LEDs are the hot new technology, and they’re here to stay. Although a novelty just a few short years ago, we’re now seeing legitimate production tools in the LED world. The Switronix TorchLED Bolt TL-BT200 is a small on-camera fixture (5.6″ x 4″ x 3″) that features 16 high-intensity LED lamps with reflectors. Bolt is unique in that half (eight) of the LEDs are 5,600°K color temperature and the other half are 3,200°K. Two individual dimmers (one controlling 5,600°, one controlling 3,200°) allow the user to dial in any color temperature between 3,200°K and 5,600°K.
It’s a great concept, and the light has good output with pretty smooth dimming down to about 20 percent, and then it gets sketchy (jumps).
There are several rubs here, however. The first is the fixture’s power source. Although it can utilize Sony DV batteries or DC converted power, the fixture requires a fairly a hefty 22 watts. (Switronix sells batteries for Bolt as well.) My review unit did not come with an AC/DC plug, so I tried to use one of my own, but it generated only 16 watts of power and I couldn’t turn the fixture up to 100 percent. So I turned to my stock of Sony NP-F960 batteries. If the battery wasn’t fully charged, the fixture would power up to only about 60 to 80 percent intensity before turning itself off. With a fully charged F960, I could get about 15 minutes at 100 percent before the light shut itself off. I could turn the light back on and use it at less than 100 percent, but if I tried to go back to 100 percent again, it would shut itself off.
The Bolt also comes with a PowerTap cable that hooks into the professional accessory power port on most higher-end professional cameras. This is not an option on DSLRs or prosumer cameras, though.
If you don’t already have Sony L Series batteries or a professional camera with a PowerTap, you’re out of luck with this fixture. I couldn’t find any listing on the Switronix web site for an AC/DC power pack for the Bolt, so you’ll have to find one of your own that can do between 12V and 16.8V at 22 watts.
Additionally, the two dimmers have no calibration to them. You’re left to guess how much intensity you’re dimming. Normally this wouldn’t be an issue, but as you’re mixing two different color temperatures, you’d better have a discerning eye.
More frustrating, if you get your color dialed in and then decide the fixture is too intense (or not intense enough), there’s no scale to dim (or increase) the tungsten/daylight dimmers equally to keep the color but change the intensity. This means you’ll be doing a lot of fiddling with the dimmers as you’re working with the fixture—and that’s a bit of a nuisance.
It’s also a very heavy fixture. With no battery, it’s just under 1.25 lb.; with the F960 battery, it’s just over 1.75 lb. That might not seem like much on the page, but when you put it on top of a handheld camera, it gets heavy very fast.
Working with the Bolt over the course of a day, I found I was able to match natural daylight coming through the window through the mid-afternoon into dusk and then magic hour fairly easily and accurately (enough to be very useful) with just some trial and error. Moving into night, I was able to work with the same fixture to balance to tungsten illumination pretty closely—although, at 3,200°K, it was a little cooler than standard tungsten light. The versatility of a fixture than can modify its color temperature is pretty extraordinary.
I used my Canon EOS 7D camera and ExpoImaging ExpoDisc calibrated gray disc to test the unit’s precision, examining the images in Adobe Photoshop to determine color temperature accuracy. At 3,200°, I found the Bolt to have good, solid color rendition with just a little green—about 2 percent high, which is hardly noticeable. All in all, very good color rendition at 3,200°K.
At 5,600° the color isn’t quite as solid—there was a higher blue content (about 3 percent over red) and, surprisingly, less green—but it was still very close to 5,600°K. The differences would be easily correctable and most likely not an issue when combining this fixture with other daylight sources.
With both 5,600° LEDs and 3,200° LEDs turned up to 100 percent, the fixture generates a color temperature of roughly 4,300°K.
Here are the photometrics I measured testing the fixture’s output:
Fixture at 100 percent with 5,600°K LEDs only
2 ft. 670 fc
3 ft. 260 fc
4 ft. 130 fc
5 ft. 84 fc
6 ft. 55 fc
Fixture at 100 percent with 5,600°K LEDs only and diffusion filter
2 ft. 90 fc
3 ft. 34 fc
4 ft. 18 fc
5 ft. 12 fc
6 ft. 8 fc
Fixture at 100 percent with 3,200°K LEDs only
2 ft. 410 fc
3 ft. 190 fc
4 ft. 100 fc
5 ft. 64 fc
6 ft. 42 fc
Fixture at 100 percent with 3,200°K LEDs only and diffusion filter
2 ft. 64 fc
3 ft. 24 fc
4 ft. 14 fc
5 ft. 9.2 fc
6 ft. 6 fc
Fixture at 100 percent with both 5,600°K and 3,200°K LEDs
2 ft. 1000 fc
3 ft. 410 fc
4 ft. 220 fc
5 ft. 150 fc
6 ft. 97 fc
Fixture at 100 percent with both 5,600°K and 3,200°K LEDs and diffusion filter
2 ft. 140 fc
3 ft. 59 fc
4 ft. 34 fc
5 ft. 21 fc
6 ft. 15 fc
I can’t say I’m a fan of the filter system on the fixture. The filter holder fits on snugly, which is good, but the filter, which is a hard sheet of milked plastic with a horizontal diffraction grating pattern that helps to spread the light, does not fit well into the holder. It’s very loose and bounces around easily. If you’re handheld and you happen to lower the camera and tilt it a bit, the filter can fall right out. It also bounces around and makes noise in the holder, which isn’t good in any situation. You’d have to tape the filter into the holder to keep it secure and quiet.
There’s one mounting point on the fixture, a 1/4-20 threaded hole, and the Bolt comes with a ball socket to cold-shoe adapter.
The Bolt is made from strong ABS plastic, so it should hold up well to standard usage, but I wouldn’t want to drop it.
Although other small LED fixtures that use AA batteries eat through those batteries at an unrelenting pace, I’d prefer that option here. It’s frustrating to be so limited in power options for this fixture.
Switronix TorchLED Bolt TL-BT200
PROS: Color temperatures between 3,200°K and 5,600°K in a small, portable fixture. Good light output.
CONS: Limited power options, heavy fixture, loose and noisy diffusion filter.
BOTTOM LINE: As one of the only fixtures on the market in its size that allows variable color temperature, the Switronix, despite its shortcomings, stands alone. It’s well made and very reasonably priced for the output.