Hi David,
I use a Sony A65 and a Sigma 105mm macro with a 10x Nikkor microscope objective fixed with a step-down ring. This is set up on a solid rig, opposite a Newport micrometer stage to which the egg is attached. It is lit with a ring flash and slave, diffused through a polystyrene cup. I then take about 40 shots, changing the focus by a couple of thou each time, and stick the images through a Zerene Stacker. It's quite tricky to get everything lined up properly, but it's a fascinating technique when you get into it. Have a look at :/
www.photomacrography.net - there are some really astonishing images there. If you're interested in trying to do some, you'll find the guys on the site incredibly helpful. I attach a non-butterfly stack to show the sort of thing that you can produce.
Tony.
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