Review: Profoto B1 Off-Camera Flash kit

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I recently worked in a studio that still had the original strobe flash packs dating back to the late 1970s. I was able to explain to my assistant the joy (and fear) of working with these flash generators, which, despite their size and weight, photographers used to take on location. Back then we didn’t have much choice, but flash technology has come a long way and the Profoto B1 Off-Camera Flash kit is a prime example of how a powerful studio flash system can now be made truly portable.

The kit featured here consists of two Profoto B1 flash heads, two lithium-ion batteries, a fast charger, car charger, plus backpack. The B1 flash heads have a nine f-stop range, from 2W to 500W, offering 1/10s stop, or full incremental exposure adjustments. The flash recycling time varies from 0.1s to 1.9s, depending on the power setting, and provides a quick burst of up to 20 flashes per second.

The lights will still fire even if they are not yet fully charged to the required power level, but this is only available when using the lights at less than full power; the consistency of the flash output will be slightly less accurate. A ‘wrong exposure alarm’ alerts you when this happens and you are shooting too quickly. I found the flash recharge time was plenty fast enough for photographing people, and felt no different from using regular, mains-powered studio flash units.


The Freeze mode gives shorter flash durations – from 1/19,000s at the lowest 2W output to 1/1000s at the highest, 500W output setting. In Normal mode, flash output is colour-balanced and gives flash durations ranging from 1/11,000s to 1/1000s. Basically, the colour output is more consistent, within +/- 20K from flash to flash, and that amount of variation increases to +/- 50K from flash to flash when used in Freeze mode.

The kit comes with two chargers – a 4.8A unit for fast, one-hour recharging and a two-hour car charger that fits into any standard car cigarette connector. A 2.8A mains unit for normal two-hour recharging is also available. A fully charged battery should provide up to 220 flashes at full power, and each flash head has a battery life indicator to help check the current battery level. Each flash unit has a 20W LED modelling light with adjustable settings, and these can also be controlled via the Air Remote TTL.

Everything about the lights has been carefully thought out and beautifully engineered. The batteries lock into position effortlessly and the head tilt control is strong enough to support any kind of light attachment. The LCD user interface is clear and easy to read in bright daylight. I also like the way lighting umbrellas slide in smoothly and are gripped by just the right amount to stay in place.

The only thing I found challenging was setting up the channel group settings for each head. This only needs to be done once, but may be more of a problem when shooting with a larger number of heads and needing to define different flash groups.

A Profoto Air Remote TTL-C unit is currently available for compatible Canon cameras that use Canon’s E-TTL II metering system, but there are plans to release a device for Nikon cameras later in 2014. For now, non-Canon owners can use a regular Profoto Air transceiver to trigger the B1 lights, though of course this doesn’t offer TTL functionality. The Air Remote unit is attached to the camera hotshoe. When the lights are used in Air mode, with the Air Remote device set to TTL mode, it can take full automatic control of the Air-synced flash heads.

In testing, I set the camera to manual mode so I had full control over the shutter speed and aperture to manage the ambient daylight exposure. When using the TTL device, the flash exposure is read and the flash duration adjusted automatically. It can be varied by dialling in the desired exposure compensation. For example, do you want the flash exposure set to normal, or to underexpose, or do you want to adjust the relative exposure settings for the two heads? This can be done by assigning the lights to different groups, such as A, B or C, which gives you full control over the power output ratios, as well as the ability to control the modelling lights.

The TTL unit also has a slanted screen, which makes it easier to view the settings at most heights. It’s smart, too. When the TTL unit is switched on, it ensures the shutter speed can’t be set any higher than the maximum possible sync speed. For example, if the shutter speed is set to 1/ 500s, as soon as you turn on the TTL unit it will reset to 1/250s (the maximum allowed on a camera such as the Canon EOS 1Ds MK III). There is also a manual mode, which bypasses the TTL for those times when you need full manual control over the flash power settings.

The two-head kit comes with a sturdy backpack to carry the two flash heads, plus room for further accessories and a side pocket for two mini stands. Each light weighs 3kg (including battery) and the total weight of the kit I took on location was just under 12kg. It’s therefore just as well that the backpack is robust and comfortable, even when hiking up a steep hill to capture the location shot shown here.

I especially liked having the ability to set the ambient exposure for the camera and manage the flash heads separately via the TTL device. All I had to do was assign a different group to each light, use the Air Remote TTL-C to adjust the relative power output for each light and let everything happen automatically. If you are shooting on location in changing lighting conditions, it’s a few less things to think about, knowing that the exposure in each shot is guaranteed to have just the right amount of flash.

At €2950, the Profoto B1 Off-Camera Flash kit isn’t cheap, and you still need to factor in the cost of the Air Remote TTL unit plus stands and lighting accessories. But for the sheer convenience and automated control you get working with the Profoto B1 lights, it’s a compelling package.

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