I was wondering what category to use; the near bees are very close, showing them much bigger than for the naked human eye, so I figured 'Macro' was OK.

This picture was taken at the limit in many respects, I had to make a lot of trade-offs - let me know what you think about those:

1. Flare vs. viewing angle. The Sigma is reasonably handling the sun in the corner and I actually like the flare next to the fast-moving arriving bees, the reflections are a little disturbing though. At 8mm, flare was not manageable from this perspective. I may try the 8mm Samyang, my 'shoot straight into the sun' lens HD DA 15mm is likely too narrow.
2. DoF vs. diffraction vs. shutter speed/ISO: I focused slightly closer than the hyperfocal distance, in order to have a chance to catch a few bees fairly close to the focus distance. Maintaining a fast shutter speed required to crank up ISO - introducing some noise / noise reduction blur.
3. Shutter speed vs. ISO vs. aperture: Bees are fast. Getting them somewhat sharp in full flight, esp. the very close ones, would require a flash (not practical in full sun and with this composition) or very fast shutter, even if that leaves room for motion-induced distortion due to the limited speed of the shutter traveling across the frame. At several meters per second, 1/3200 still means around 1mm of movement, easily blurring the insect. Close to the hive arriving bees are much slower and it shows. I could think of a composition of a long exposure (no bees) and a flash shot with an ND to darken out the background sufficiently, only hitting the close-by bees. Would that be feasible - aside from attaching filters to this lens? Needs a strong flash, thus long burning duration and blurrrrr?

Another option would be to follow the picture concept and post process to simulate bee vision (segment eyes). That would eliminate any concerns about sharpness.