Shooting TTL with the Profoto B1’s

I’ve never been the world’s biggest fan of TTL flash, and as recently as a couple of weeks ago I was pointing out that despite the fact that my shiny new Profoto B1 heads are equipped with it, I’ve hardly touched it.  However, just the other day it was pretty useful, and I found myself being very grateful for it’s presence.

Let me backtrack a little, and get on my soapbox before I sing it’s praises though.  Having been shooting as long as I have, (I almost predate TTL flash) in those days you either used auto aperture or manual on your flashguns.  In the case of studio/mains flash, manual only – there was no choice.  I was perfectly happy with that situation most of the time – the quirks that auto aperture threw up (things like shooting people in reflective vests etc) could usually easily be solved by switching to manual, or dialling in some compensation.  For the most part, auto aperture was ideal when you were dealing with fast moving situations, and for any situation where you could lock down the subject and the lighting, manual was always the answer.  For me, this hasn’t changed – I still use manual flash settings along with manual exposure settings at least 95% of the time.

TTL Setup
Setup shot – 1 B1 head inside 7ft parabolic on the right, and a 2nd B1 in a beauty dish in the background, just left of Vittorio’s head. Note how much area the light has to cover – hence the whole “let’s try TTL” thing.

Along came TTL, and like any new technology I was initially a bit resistant.  My first experiences with it (A Metz 45 CL-4 on a Nikon F90x) were not impressive, and even a generation later with D-TTL I still wasn’t happy.  My main complaint has always been that TTL mode seems to give such wildly different exposures, even of the same subject.  I find that if I reframe even slightly the processor inside the camera decides to go off on a tangent, and pump out way more or way less flash, when the main subject hasn’t moved.  Needless to say, inconsistency like this isn’t something I’m that fond of as a professional!

Despite all the extremely complicated maths that goes into metering TTL, I’ve never understood why, with modern cameras and coupled lenses which can send distance information to the processor, the camera can’t simply do a distance-Guide Number-ISO calculation based on the focus point, and just leave it at that.  But perhaps that why I’m not a camera designer…..

The fact of this inconsistency is why in ANY situation where I’m able to control the lighting, I will always use manual.  Given how much I use studio/mains flash without any automated options anyway, I’ve rarely had the choice, but the logic behind this is that if I’ve spent some time to get the shot to look how I want, balancing the lighting in certain ratios, and perhaps mixing in some ambient light, why would I then leave a large aspect of the exposure to the whim of my camera’s software by setting the flash to TTL, or worse, shooting in an auto exposure mode?

The times I use TTL these days tend to be shoots where both myself and my subject are moving.  There’s a decent chance that shoots like these will also be outside, and as such will involve rapidly changing ambient light as well.  In cases like this manual mode is less effective, as the difference in exposure between say, bright sunlight and the shade of a tree, and something that’s 2 feet from the flash or 10 feet from the flash is pretty big.  Unless I’m totally on the ball 100% of the time, and have got the time to be continually altering my flash output and my exposure, TTL gives me a slightly better safety net.  I find it’s very rarely perfect, but will be closer to OK than using manual and missing by miles if the parameters change quickly.

Profoto B1 TTL flash
Vittorio starting his run by jumping over, then riding, a trap bar. Lit with TTL flash.

B1 TTL in action

So, to bring us up to date, I was shooting last week for Multipower with the extremely impressive Vittorio Brumotti, a freestyle cyclist.  Besides me shooting several profile shots, and staged “hero” shots of him pulling moves on the bike, we needed to video him freestyling through the gym we were shooting in and we needed to film it in one take for it to work.  Now, obviously, there’s nothing to stop me from simply cranking up the ISO on the D4, opening the aperture a bit, and shooting with the ambient light that the video guy has set up, and I did, because we needed as many shots as possible (Vittorio attempted the ride several times – obviously).  However, ambient shots like this never look as good as ones that are lit, plus freezing action isn’t great, and even with a D4, noise creeps in at higher ISOs, so using flash would definitely help.

Profoto B1 TTL flash
Bunny hopping over boxes, lit with TTL flash

Problem is, he’s riding through such a large area that I can’t really use manual exposure – the settings may be perfect in one area, but by the time he’s 20 feet away, they’ll be different.  At this point a little voice in my brain said “your B1’s can do TTL you know Tom…” and I thought why not give it a go.

TTL 4
Almost identical shot, this time purely ambient. You can’t tell from this resolution how noisy it is, or how unsharp it is compared to the flash version.

The results weren’t too bad at all, I’m happy to say, and certainly better than purely ambient shots.  If my D1’s did TTL as well, I’d really be laughing, but I find it interesting that even in frames that are almost identical the exposure STILL varies quite widely from frame to frame.  Compare them with ones taken later in the day with everything set to manual (and, admittedly, 4 lights not 2) and there’s a distinct difference in quality, but partly that’s because in following Vittorio around, I can’t “set” the lighting in one spot – it’s got to be quite a broad brush.

Shooting TTL with the Profoto B1
Vittorio demoing some moves, shot with good old-fashioned manual flash – 4 of them to be exact.

Thinking ahead, I’ll be interested to see if I can combine the TTL of the B1’s with the manual output of the D1’s.  This would allow me to create a level of “ambient fill” with the manual lights, to lift the overall light level inside a venue, and then the TTL to follow any moving subjects within that space.  Definitely something to chew on.  Next time I’ve got a top Italian freestyle cyclist in the gym, I’ll give it a go.

Crikey, I’ll be using program mode and auto white balance next.  No, actually, no I won’t.


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