Christian, have you tried a 2x TC on a fast macro for such shots? I've used the Vivitar Macro 2x TC on both a Kiron 100mm f2.8 macro and the K 135mm f2.5 with surprisingly good results.
Christian Skofteland wrote:
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For extra magnification (2x and beyond) I use stacked lenses but my results haven't been great, but that's a user problem....

