It is no small feat to snap crystal clear shots of the very rapid movements of insects and their wings.
"The external shutter opens in about 10 milliseconds 10x faster than the DSLR can react and that is why its important to have access to a very fast acting external shutter. If the camera’s shutter was used the insect would be out of the field of view before its shutter could open. Because of this, high speed photographs are typically done in a darkened room to avoid this lag (ie on bulb mode). An external shutter allows insect to be captured in full sun. "