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:
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.