Thanks Tony and Andrew for the tips, especially to set to minimum focus and manual... I'd been using the AI servo mode and trying to track the little beegers
. I'd recently worked out the benefits of flash and that's helped me a lot. I've got the 580EXII and after the 100mm F2.8 is my next favourite bit of kit! I haven't been using a diffuser though and I can see that would help as I lose details in shiny insect bits. thanks again guys and GREAT pics. cheers, Rob