So one eye-friendly way to observe the sun (at least in summer) is to stand under a deciduous tree canopy and look down: under suitable candidates there will be several foliage-diffracted circles in evidence among the general shadow.

Do these reflect the solar disk, or are they circular due to a different process? If the former, would it be possible (with enough magnification) to get similar images during a Venusian transit?

> "At the time we were all making astronomical observations at a dollar per figure, I realised that for centuries we had only one model for this scientific discipline..." — not AAJARENyC, "Transit of Venus" (1977)