Roy used to run a company on the East Coast – Fotronix Inc., which was responsible for producing a range of HSF units known as the StopLight range. The principal product was the StopLight SL-80, which was sold internationally to many photographers, most of whom are still using the system today with great results. The StopLights were designed to very different specifications than the VHSF system – the main requirements being for portability, weatherproofing, fast recycle time, and the ability to stop most fast-moving wildlife action, such as insects and birds. The final specifications are shown:
StopLight SL-80 Specifications:
Guide Number: ~100 in feet, ISO 100
Flash Duration: ~ 1/15000th of a second (~ 67 microseconds)
Recycle Time: ~1 second
Size: ~ 9” cubed
Weight: A few pounds
Power Supply: 12V sealed lead acid battery (1.2AH)
Charging Current Consumption: ~ 13A
This was produced from 2002 to 2004 in the US by Fotronix Inc. out of North Carolina. It was designed by a photographer, for photographers. A 9x9x9 inch sealed polycarbonate unit capable of 1/15000th of a second flash duration, yet with a Guide Number of around 100 at ISO 100. Weatherproof and portable, it is the ideal system for photographing hummingbirds. Each head can be setup in isolation with its own battery (attached to the mounting bracket), or used a part of a 4 or 6 head system with a common supply, via a ‘StopBox’. They were light, practically indestructible, and perfect for freezing fast moving wildlife subjects such as hummingbirds. The units operate at an internal voltage of approximately 1300 volts, yet the only external voltages were the 12V supply (6 amps) and the flash synch voltage (5V). The flash tubes were purpose-built for these units, and offered color corrected tubes to 5250 degrees Kelvin – much warmer than more traditional high speed flash units.
Quad Set
This was the most popular system sold by Fotronix, and incluced 4 heads, 4 15 ft connecting cables, a 4 way StopBox, and a power cable for a single 12V supply or battery.
6 Head Set
This set provided the most flexibility. In addition to the 2 extra heads, it utilized the 6 way StopBox, which had the added dimension of enabling each head to be triggered separately, enabling stroboscopic effects.
