BRONCOLOR – Siros L – Cordless Studio Strobes Announced



High end Swiss lighting manufacturer Broncolor have announced the Siros 400 L, and 800 L, fully cordless battery powered studio strobes.

The Siros L do not provide TTL or High Speed Sync, though Broncolor are possibly still ahead of the game in recognizing the demand for serious studio quality cordless lights, both for indoor and outdoor use.

UPDATE 21 Sep 2016 – The Siros L do now provide a HS mode for High Shutter Speeds, with the introduction of the RFS 2.2 transmitter units.

The Siros 800 L and 400 L provide fast flash durations, fast recycle times, and color stability often found in AC mains powered lights.

And most telling, the Siros L provided a bright 25W LED modelling light, with a color temperature of 3000 K, to match, and work nicely combined with, the halogen modelling lamps provided by the Siros mains powered studio strobes.




At 800Ws Broncolor are also claiming to have created one of the most powerful cordless compact flash units currently available in the Siros 800 L.

The smaller Siros 400 L provide half the output, though with an advantage in size and weight. And also provide 440 full power flashes per battery charge, where the 800 L provide 220 pops using the same battery.

Total weight with battery installed is a substantial 4.3kg for the Siros 800 L, and 3.7kg for the 400L.






Maximum Watt/Seconds 800 Ws
Control Range 9 stops in 1/10 or full-stop intervals (2-400Ws)
Guide Number With L40 Reflector: f/32+8/10 at 6.5′ (2 m) and ISO 100With P70 Reflector: f/45+6/10 at 6.5′ (2 m) and ISO 100
Recycle Time Eco Mode: 0.04 to 1.9 secNormal: 0.03 to 1.2 sec
Flash Duration Min. Energy: 1/4400 sec (t 0.1) / 1/7400 sec (t 0.5)Max. Energy: 1/250 sec (t 0.1) / 1/700 sec (t 0.5)Speed Mode:Minimum Energy: 1/8700 sec (t 0.1) / 1/18000 sec (t 0.5)Maximum Energy: 1/250 sec (t 0.1) / 1/700 sec (t 0.5)
Color Temperature Max. Energy with P70: 5500K
Modeling Light 25W LED, 3000K color temperature
Triggering Manual trigger button, photocell, sync cable, built-in Broncolor RFS 2.1 receiver
Remote Control Using bronControl app for mobile devices, or RFS 2.1 transmitter
Flash Ready Indicator Visual and audible (switchable)
Power Li-Ion Battery: 28.8 V / 2.5 Ah / 72 WhCharging: 70 minutesFull-Power Flashes: 220
Other Features Sequences (flash series) up to 50 flashesUSB connection for software updatesSpeed Mode for fastest flash duration
User Replaceable Flashtube Yes
Changeable Reflector Yes
Auto Dump Yes, when power is reduced
Operating Temperature 14 to 140°F (-10 to +60°C)
Dimensions Head: 14 x 5.1 x 7.1″ (36 x 13 x 18 cm)Battery: 3.3 x 4.3 x 2.2″ (8.5 x 11 x 5.5 cm)
Weight Without Battery: 8.2 lb (3.7 kg)Battery: 1.3 lb (0.6 kg)




The Siros L do not provide any mains power adapter, though the 28.8 V, 2500 mAh, battery fully recharges in just 75 minutes.

So if there is mains power available, a second battery can easily be charging while the other is use. That way keeping the Siros L cord free as they were designed to be.

The battery also provides a built in charge level indicator.




As with the mains powered Siros strobes, the Siros L provide built in Wifi, which allows full remote control from an Android or iOS mobile device using the bronControl app.




Basic remote power control (in full or 1/10th stops) is also available from the Broncolor RFS 2.1 radio transmitter mounted on the camera. Though no power level indication is displayed on the transmitter’s LCD screen.

The RFS 2.1 transmitter will fire and control the Siros L and other Broncolor strobes from up to 200 meters outdoors, and up to 50 meters indoors.




Broncolor, also known for their beautifully engineered parabolic reflectors, are keen to point out the Siros L provide a fully exposed flash tube, which allows a very wide spread of light. Unlike the rival Profoto B1 for example which use a more recessed flash tube design.

The Siros L are also compatible with the full range of Broncolor Light Shapers (softobes, reflectors etc).




The real features of the Siros L are the impressive 0.03 to 1.2 sec recycle times in Normal Mode, and 0.04 to 1.9 sec in Eco Mode.

As well a the motion freezing fast flash duration’s as short as (t0.1) 1/6200s for the 400 L, and 1/4400s for the 800 L, while retaining stable color temperature across the power range.






The Broncolor Siros 400 L and Siros 800 L are available now from around $2050, and $2350 respectively –

Siros 400 L – Adorama, B&H Photo

Siros 800 L – Adorama, B&H Photo

RFS 2.1 Transmitter – Adorama, B&H Photo


Broncolor – RFS 2.2 Transmitter with HS mode

Broncolor – Website


  1. JL Williams 3 years ago

    The specs say those very short flash durations happen only at low power settings; at full power the numbers (1/250 or 1/700 depending on how they measure) don’t seem as impressive…?

    • Author
      Flash Havoc 3 years ago

      Hi JL,

      That’s common with IGBT strobes, the shortest flash durations are at the lower power levels.

      The difference with the Broncolor lights it that they provide stable color temperature across the power range in speed or regular modes. (ECTC – Broncolor “Enhanced Color Temperature Control”).

  2. Dan 3 years ago

    From what I am seeing these have been out for a while. I have access to Broncolor Scoros lights and I am very impressed with them. If these are even near the same quality they are a good deal.

    • Author
      Flash Havoc 3 years ago

      Hi Dan,

      The AC mains powered Siros have been out for some time, though the cordless Siros L are not available until around mid July (2016).

      • Dan 3 years ago

        My mistake. I see to reach HSS you have to order the version with a Pocketwizard receiver. The Godox Ad600 is looking better all the time.

  3. Robert Collins 3 years ago

    While the rash of new battery operated monolights is welcome, I cant help feel that the size and weight of some these rather negates their portability

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