One thing that I always notice but that is really difficult to take pictures of: How bubbles on a water surface focus the light into little stars on the ground. See?
Can you see which bubble corresponds to which star?
Almost as exciting as this:
Remember this, Anna? :-)
I was searching the web for some explanation of the star bubble refraction phenomenon and found nothing but your blog. Do you have a theory for what’s happening? Looks like some weird coma-like aberration.
I guess it’s a combination of both tangential and sagittal astigmatism