Profoto B1 – Has TTL LOCK ! – the Hidden OCF Revolution ?

The recently released Profoto B1 portable flash is certainly getting a lot of attention, but what may be the most revolutionary feature to this flash appears to have gone mostly unadvertised and unnoticed.

The new Profoto B1 is a self contained, lithium-ion battery powered 500Ws monolight, with the option of TTL when using the Air Remote TTL transmitter.

TTL metering itself is a first in a flash unit of this power, but Profoto have slipped in a feature which may turn out to be much more revolutionary. That feature is TTL Lock!

Profoto Air Remote TTL

TTL Lock, in short, is the ability to take a shot with automatic TTL metering, and then lock that power level in by switching to manual on the transmitter.

The TTL exposure is converted to a manual power setting, so you can then tweak that power level in manual or just keep shooing with consistent exposures. If the subject moves away from the light, you can quickly re-meter the light in TTL and switch back to manual again.

TTL Lock, or what I called “Hybrid TTL” is a concept I used to bang on about all the time, going back to development of some of the first TTL triggers in 2009 with the Pixel knights. This was something I was really passionate about, because it just seemed like common sense for the fast paced way many wedding and portrait, and even commercial and media photographers (I have been working with to provide portable gear solutions) often need to work.

Nikon, and even Canon, already have TTL lock now to some degree, but that still misses the most important part, which is the ability to tweak the results in manual after you have locked the exposure. With a multiple light set up this is the most intuitive way to meter super fast, and then tweak each light as needed.

There is a huge time advantage to this because you don’t even have to set any power levels on the flashes to start with, let alone take a meter reading for each light. This can be a big advantage for people trying to capture a number of poses and set ups in a short time.



There is however one critical thing currently still missing in the Profoto system for this to work efficiently the way I would prefer, and that is FEL lock (or Flash Exposure Lock).

To me FEL is critical because it takes all the randomness and guess work out of TTL. Its like a spot meter for the flash. So you simply aim the cameras center focus point at any small area with the tone you want to expose correctly, and the TTL is almost guaranteed to expose that correctly first go. So very often this is just aimed at peoples face and skin tone so that is exposed correctly. And the great thing is you’re generally focusing in that area on the eyes at the same time anyway, so its very fast and natural.

Otherwise I’m not a fan of TTL metering and guesswork anymore than anyone else. But this is accurate metering, though fast and automatic, even while you take a photo.

This is why I call it Hybrid TTL, because its really using the best of both worlds, you’re really controlling the metering, quickly and accurately, while the system is running around setting all the power levels for you in an instant. And if the subject moves you can re-meter a number of lights very quickly again.

The B1 and Air Remote TTL have USB ports for firmware updates, and there are strong hints there may be more features to come, so hopefully FEL will be one of those. Profoto have already made comments about working on High Speed Sync for the B1.


This is the way I explained Hybrid TTL in one of my emails to manufacturers in early 2010  –

This is the concept to revolutionize the TTL trigger!

Hybrid TTL !!

There is a big gap between manual flash and TTL flash use. If you ask any photographer what they don’t like about TTL they will tell you its not consistent like manual! That often makes manual easier even though it takes much longer to set up at the start.

The big problem with trying to use TTL instead of manual is there is currently no easy way to keep that consistency!

The problem then with Canon and Nikon flash system is they simply do not have any way to keep the exact same exposure as you just got with the last TTL shot, and then adjust from there!

What is needed is to be able to keep (store) the same exposure as the last TTL shot and then simply add or subtract light to that (in 3rd stops) to refine the exposure to what is wanted. And all the next shots will then be exactly the same (consistent) exposure until we decide to change (or the subject moves for example) we can then shoot a TTL shot again to clear the old exposure setting.

This means you can now combine manual and TTL in…. HYBRID TTL!!

Using TTL to very quickly get close to a correct exposure and manual from that starting point for fine adjustment and to keep the next shots exactly consistent.

This would also allow you to set up exposure for a number of lights (groups) very fast!! You can have a TTL ratio already set so again the TTL exposure is already very close to what you want, then quickly refine each group and each shot again is consistent after that.

You could then dial all lights up and down together at their current ratio to allow for aperture change on the camera for example.

This would seriously revolutionise the use of TTL, and bring the manual only user (90% of strobist) to the convenience of TTL.

I’m very serious, this will be the future of off camera TTL speedlight systems.


Keep in mind that was back when I was getting started, and had to over emphasize a little to try and get anything heard. But I still believe TTL Lock (or Hybrid TTL) can really change portable off camera lighting, particularly for fast paced work.

Hopefully this does get a lot more attention to come, and TTL Lock / Hybrid TTL becomes implemented more, and further refined. Because there is so much unused potential with TTL metering for off camera flash use. Props to Profoto for really getting the ball rolling.

And they make it seem so simple and obvious. Profoto make this gear so that anyone hiring them can simply pick them up and use them without studying a manual. If only Canon and all the other trigger and flash designers would think like that, we would have a whole world of faster user friendly interfaces etc.

Neil van Niekerk touches on the TTL lock feature in his great B1 review here, but I don’t think he has even realized just yet the full potential of what this is all about.

I realise this is not for everybody, but for the right people the B1 is going to be an incredible flash unit. A lot of people are crying out for HSS, and smaller units already, and you never know Protofo may just be getting started. They have certainly started to acknowledge the large rise in speedlite use professionally as well.


B1 Price and Availability –

The B1 500 Air TTL flash is now available for pre-order for $1995 – B&H Photo – Adorama
The Air Remote TTL-C Transmitter pre-order for $395 – B&H Photo – Adorama
(Nikon version Air Remote TTL-N coming in 2014).

B1 Overview.

Profoto Website – B1 500B1 500Air Remote TTL.

  1. Armin 7 years ago

    Interesting read. Haven’t thought about that concept yet, but now I want it.

    Any plans to lobby the manufactures like Yongnuo, Phottix, Godox, Jinbei, …? I see you’ve done in 2010, but things have changed since then and I guess chances are way better now.

  2. Earle 7 years ago

    I saw that video and was truly impressed. But at that price point it’s not a hobbyist’s piece of gear (or many professionals). Still I could see rental houses cleaning up with these for location work. If it all checks out, worth their weight in gold.

  3. photomy 7 years ago

    “Nikon, and even Canon, already have TTL lock now to some degree, but that still misses the most important part, which is the ability to tweak the results in manual after you have locked the exposure. With a multiple light set up this is the most intuitive way to meter super fast, and then tweak each light as needed.”

    Not sure about Canon, but my Nikon D700 allows +/- 5 stop adjustments in 1/3 stop increments after TTL flash is locked via exposure compensation dial on top of the camera which only changes flash power if in Manual Exposure Mode (which most people use for flash). This cannot be beaten for speed and ease of use.

    • plevyadophy 7 years ago

      @ photomy

      I don’t quite understand what you mean.

      Can you explain that Nikon flash thing again, giving a step by step account/example?

      I am not quite getting the Manual Exposure Mode reference in the context of what you are saying.

      Thanks in advance.

    • Author
      Flash Havoc 7 years ago

      Hi Photomy,

      Is that only for the flash on camera though, or can you use that with the commander and off camera flashes, and with a number of groups/lighting ratio?

      I’m not familiar with Nikon but I realise they have had a TTL lock for a while, but I’m pretty sure its not the simple intuitive system of switching to manual and showing you the manual flash power so you can tweak a number of lights from there. And obviously they don’t have a radio flash system yet either.

      • tommy 7 years ago

        Yes, can be done off camera with the proper master.

        Step 1 Attach master or flash on camera and set Nikon body to Manual Exposure mode.

        Step 2 in iTTL or BTTL press flash lock button on Nikon body (needs to be programmed from menu options as to which button). Pre-flash is sent, scene measured for required flash power, and stored in memory.

        Step 3 Press Exposure Compensation button at top of body and increase or decrease flash exposure by increments that were selected in menu options. I use + – 5 stops in 1/3 increments (I almost never use the real flash exposure control on the body because it is more limited and harder to reach). This will increase or decrease flash power from the initial measured amount needed (Step 2). To leave flash lock and go back to regular iTTL press flash lock button again. To lock again, press flash lock again.

        For Canon: I believe that Exposure Compensation while in Manual Exposure mode does not behave in the same way with a flash attached. NOT SURE, maybe it actually changes aperture or shutter ?? Not the case with Nikon. With Nikon, the default is flash power adjustment only.

        Hope this helps.

        – tommy

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