Interfit Photographic’s S1 is a 500Ws strobe with a built-in battery that supports high speed sync (HSS) and TTL for Canon and Nikon cameras.
The S1’s interchangeable lithium ion battery is good for up to 350 full power flashes in either manual or TTL modes and up to 400 full power flashes when shooting in HSS mode. The S1 weighs 6.3 pounds with battery included.
You can also run the flash off of AC power thanks to the included multi-voltage AC adapter.
The flash works with an optional remote for Canon and Nikon cameras ($100) to enable TTL metering. The S1 has a seven stop power range which is calculated in 1/10th stop increments when shooting in TTL mode with +/- 3 stops of exposure compensation and the ability to manual adjust the flash within 1/3 stop.
When shooting in manual mode, the S1 is controllable in 1/10th stop increments with access to HSS mode for shutter speeds up to 1/8000 sec. You’ll enjoy shutter speeds of 1/250 sec. in normal sync mode. HSS mode uses the top four stops in the S1’s power range and is manually adjustable in 1/3 stop increments.
Flash durations clock in at 1/1,000 sec. at full power and down to 1/9,000 sec. at minimum power. Interfit says the S1 maintains a consistent 5700K (+/-100K) color temperature throughout the power range.
The S1 features an aluminum body with a frosted glass diffuser dome and a Bowens S-type mount. The light is firmware upgradeable via mini USB (cable included). It also offers a 10w LED modeling lamp.
The S1 will retail for $1,000. Additional batteries will set you back $200. Interfit will also sell a version of the S1, the S1a, that only runs off of AC power for $600.
Both units are expected to ship in December.