The Left Hand Flash

I tried a new (to me anyhow) flash technique over the weekend. I was shooting candids quickly in a fairly tight space and getting the flash pointed at an appropriate surface for each shot was challenging. After some fiddling with other approaches, I finally just picked up the 430EX and held it in my left hand, so I was shooting one handed with ST-E2 IR flash trigger mounted in the hot shoe leaving me free to direct the flash with my left hand.

So, how well did it work?

Handling the camera one handed worked reasonably well. I was mostly shooting at f/2.8 and still getting excellent focus. The only real problem I had focusing was occasionally firing the camera with the half press of the shutter button I was capturing the focus point. The biggest issue with camera handling was keeping the camera level. I had a lot of shots where the horizon was significantly out of level.I was shooting with the the 35/1.4 and 50/1.4, both of which are reasonably lightweight and lightweight lenses. As it was I noticed my right hand was getting tired; a bigger zoom might have been a problem. Of course a zoom is less useful in this scenario because the left hand is busy with the flash and can't ride the zoom ring anyhow.

The flash was somewhat more problematic. I lost around 10% of my shots because the flash didn't fire. Usually this was due to holding the flash with my hand covering the IR transceiver. That said, it was definitely a boon to be able to pick my bounce location quickly on a shot by shot basis.

The biggest problem I had was that the bulk of that the majority of my shots were between 1/2 and 1 stop underexposed. I had the camera on manual (IS0 400, f/2.8, 1/100ish) and was relying on ETTL-2 to set the flash power for proper exposure. I have a few theories that I need to test as possible reasons for the consistent underexposure:

There were a lot of white surfaces in the scenes and a brightly lit curtain in the the background of many shots. The metering may have been underexposing because of the backgrounds. If that is the problem then I just need to get better at riding the flash exposure compensation. My most successful metered flash shots have been when the background was 1-2 stops underexposed. I wonder if ETTL-2 is calibrated with that in mind and tends to underexpose when the background is bright. Certainly if I had dialed in +2/3 EV exposure compensation for the whole shoot I would have been much happier with the end results.

I have seen warnings about focus and recompose with flash exposure metering. The way I had the camera set up it was metering when I focused rather than when I took the shot. That is SOP for Canon Evaluative metering, but I have read (but never understood) warnings that it is problematic when using a flash. I am going to try using the * button for AF-lock, changing the metering mode, and fiddling with the AF-lock custom function to see if I can improve the flash metering.

It is possible that many of my bounce surface choices were costing me so much light that I was exceeding the power of the flash. That seems unlikely--I wasn't noticing long recharge times on the flash and some of my bounce locations were very close to my subject and the shots were still underexposed. Still, it is a theory worth exploring. I wish Canon would put the flash power in the EXIF; it would make diagnosing flash exposure issues much easier.

The whole experiment was successful enough to give me some good shots after some exposure tweaks in Lightroom. Hopefully I can work out the kinks and turn it into a reasonably reliable technique in my toolbox. On the whole though given the reasonably bright light levels I was working with I am not completely convinced I was better off using a flash. Clearly there were some cases where I could get light on to a shadowed face, but other shots would have had quite nice window light without the flash. While the results with the bounce flash are clearly superior to direct flash as a group they still (at least to my eyes) had that artificial flash light feel. Another flash technique I need to work on at some point is turning the darn thing off when it isn't helping me. Possibly that is a good use for the custom setup feature on the mode dial. That, hopefully, will be the subject of another blog entry.