Do you know if there are any options where there are two arms? A buying version of the DIY of Surapon. I was thinking today after posting here, that it would be great if one existed with a type of arm like the gorillapod; that are flexible in all directions, but still stiff enough to not move when taking a picture. Straight arms would be a good second.
BTW. What is your opinion on the family of angles point I made? I would assume that the options from Canon runs the risk of creating strong direct reflections?
There are a few options like that which turned up by searching 'macro flash bracket' on Amazon. But...brands like CowboyStudio and DSLRKit don't inspire confidence, and the reviews are consistent with that. There's the Novoflex UNIMARM that I'm sure would work well, but it's not cheap.
You're right about the 'family of angles' issue. Plus, the reflections from a ring light are quite characteristic and can be distracting if not removed in post. Also, when considering reflection angles you have to account for convex shapes. With water drops, insect eyes, etc., you're almost certain to get reflections in the shot no matter how you position the flash(es).
Personally, I have a pair of Wimberley F-2 macro brackets (in addition to the RRS B91-QR, and the Manfrotto 233B which I don't use much and should probably sell). They are very flexible (not quite a gooseneck arm, but close). I usually use them with the MT24-EX twin heads for more positioning flexibility than the Canon ring that attaches to the end of the lens. However, they are strong enough to support a 600EX-RT.
Thank you Danski, and Neuro. The F2 looks quite promising, and I like the fact that you can use it with the 600.
I did not think about the convex shapes, so it would be hard no matter what, but at least you can get more pleasing results.
Again, thank you for your answers