Optics: a 16 cm telescope cannot hold anything farther than about 23-30 km in sharper focus than the Sun; for the Sun to look blurred on Bonilla's photo, the body was within about 0.6-4 km

scripts/bonilla_focus.py. A lens focused at distance d blurs objects at infinity by about A/d; the blur is hidden by diffraction while d > A^2/(2 lambda) = 23 km (visual) or 30 km (blue-sensitive plate). At the 2011 paper's nearest distance, 538 km, Sun and body would differ in focus by 0.06 arcsec, far less than the air's own blur. A Sun edge blurred by 0.3-2 mm on the 66 mm print needs the body within 3.8-0.6 km. Sizes and speeds from the print (0.9 x 0.65 mm) and the 1/3-1 s crossings: at 1 km 13 x 9 cm, 9-28 m/s; at 2 km 25 x 18 cm, 18-55 m/s (small birds such as swallows or swifts); at 100 m 1 cm, 1-3 m/s (insects). Sun at 32-59 deg altitude in the east at 8-10 a.m. (Astronomy Engine), so a body 1 km out was 530-860 m above the observatory. Needed flux at 1-2 km: about 8,000-15,000 bodies per km of front per hour, within the range of strong migration pulses measured by radar; at 100 m about 150,000 insects per km per hour. The Moon test cannot separate the Moon from the planets (both far beyond 23 km): it only shows his focus was set short of infinity. Bright trails off the disk fit sunlit feathers or wings seen against the light.