Nikonian72 Loc: Chico CA

I read ISO 400, 1/160-sec at f/6.3. When I switched OS from Firefox to Chrome, I lost the application that displays camera settings.
Are you interested in increasing your DoF? If so, consider shooting at f/16, and increasing the output of your 550EX speedlight to compensate. Nearly all of us shoot manual camera settings and manual speedlight setting. Your shutter duration of 1/160-sec is quick enough to eliminate ambient light from influencing exposure.

rafikiphoto Loc: Spain

Thanks for the tips Douglass. A larger DOF would bring the proboscis, antennae and front legs into focus so I would use a smaller aperture next time. I think I will be more relaxed on a future opportunity so will experiment some more. One question about flash if I may: given the often fleeting window of opportunity of many subjects and perhaps a need to quickly change position/angle when handheld, is there not a place for ETTL?

Nikonian72 Loc: Chico CA

You can experiment with camera-controlled speedlight output, of course, but you will find manual speedlight much better suited to true macro. We all tried ETTL, but the majority of hand-held macro set-ups with manual speedlight rely on just a little bit of experience. You can get this experience shooting inanimate objects, like small flowers, or flower parts, etc.

Every speedlight model has a different max output. Take a look at this thread with chart & updates: http://www.uglyhedgehog.com/t-208134-1.html
I use a more powerful speedlight, so my recycle time is shorter at lower output, usually 1/16 power at ISO 200. A Canon 550EX will require higher output, most likely averaging 1/2 power at ISO 200.
Once you know your "normal" manual speedlight output, you can easily adjust to higher output for darker subjects, and lower output for lighter subjects.

rafikiphoto Loc: Spain

I understand. Thank you, and for the link.

napabob Loc: Napa CA