I received a new 50/2.8 macro today, and it wasn't doing well with viewfinder focusing. I shot a robin outside (through sliding glass door) then popped on the smc-A 50mm f/2. The robin was still there, and clarity and focus-confirm matched up better with this lens. As I was about to shoot a blur hovered briefly by the robin, by the time I clicked the hummer was just a blur -cropped here to be at the center of the image.
So hummers can photobomb just like people!
oops saved as Abstract - oh well the hummer counts