Fotronix StopLights

Roy used to run a company on the East Coast – Fotronix Inc., which was responsible for producing a range of HSF units known as StopLights. 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) (t0.5)
• Recycle Time: ~1 second
• Size: ~ 9” cubed
• Weight: A few pounds including battery
• Power Supply: 12V sealed lead acid battery (1.2AH)
• Charging Current: ~ 7A (for ~1 second)

This series of high speed flashes 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 as 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 (7 amps) and the flash synch voltage (5V). The flash tubes were purpose-built for these units, and offered color correction at 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.

This system gave photographers the flexibility to use each head in total isolation, or have a single 12V power supply for all 4 heads, along with a single synch input for all 4 heads. The 12V battery would be attached to the yellow cord, which was then plugged into the StopBox. Up to 4 heads were then connected to the StopBox via a 15ft heavy duty cable. This cable provided both power and synch to each head. You will notice in the photograph above there are two synch leads nestled inside the yellow cable. The photographer had the choice of a PC flash connector from the camera, or a 3.5mm (PocketWizard etc) to synch the four heads.

The StopBox had a green ‘Test’ button, a waterproof synch input connector (for either of the two synch cables) and then a charger input socket. An 18V DC adapter (supplied) could be plugged into the StopBox to charge the 12V sealed lead acid battery when connected via the yellow cable. This was a complex 4 stage SLA charger that was incorporated into the StopBox design for convenience.

When the StopBox 4 was employed (The 4 head StopBox was called a StopBox 4), all heads fired simultaneously.

6 Head (Turbo) Set
This set provided the most flexibility. In addition to the 2 extra heads, it utilized the 6 way StopBox 6T, which had the added dimension of enabling each head to be triggered separately, facilitating complex stroboscopic effects.

The 6 head Turbo set enabled everything the Quad set could do, plus a lot of extra flexibility. Obviously, one to six heads could be connected to a single power supply, and the charging current was dynamically increased to produce a cycle time of around 2 seconds for 6 heads. You will notice in the image above that the StopBox 6T is much more complex than the StopBox 4. Each head has its own dedicated synch input if required, however if it was not used, all heads would fire simultaneously. For stroboscopic effects, typically a number of PocketWizards were employed, with various delays, however any of the many folks out there that possess one of these systems could now utilize the Flash Sequencer from Cognisys. A very useful piece of gear. The list price (from memory!) for this system was around $5000.00 .

Individual Components of the StopLight SL-80 System:

StopBox 6T

This was the heart of the 6 heads system, as described above. Here is an image of the box, which also included a synch out connector.

The StopBox 6T

The power cord for a single SL-80 to be connected to a local battery – see further below.

The power cord to connect a StopBox to a single battery

The SBC-15 cord – a 15 foot cord that connected a StopBox to an SL-80 head. Includes power and flash synch.

Closer detail of SBC-15 cord, showing waterproof connectors

PC flash synch cord with waterproof connector

PocketWizard flash synch cord with waterproof connector. (Mono 3.5mm jack)

Detail of StopLight SL-80 rear panel, when connected to local battery. This battery was good for around 300 full power flashes

Full rear view of SL-80 with both battery and synch cord connected

Front and rear view of a single StopLight SL-80 Flash

This entry was posted on Monday, August 29th, 2011 at 2:26 pm. It is filed under Featured, Flash, Gear, High Speed Flash. You can follow any responses to this entry through the RSS 2.0 feed.