Me and Roy Halpin were talking about certain advantages and disadvantages that both conventional Photography and Digiscoping have one of the main reasons was the focal length reach to small passerines especially in a crowded area such as the Magee Marsh Boardwalk that pretty much hinders the big 500 to 600 mm lens useless exspecially at peak hours . So many Photographers resolve this issue by using a 300 to 400mm hand held system ,,that is good when the Bird such as a Warbler is no more than 15 feet distance from the lens with some cropping maybe adding up to about 700mm .
So me and Roy using both conventional and Digiscoping gear did a test on a Cerulean Warbler at about 100 feet both shots are uncropped .
Roy was using a Canon 7D with a Canon 300mm f4 lens.
I was using a Kowa 884 with the Sony RX100 with the 25/60 Wide Zoom eyepiece.
I was Zoomed to about the halfway on the optical Zoom on the RX-100, the eyepiece was at about 40 power giving me about 2800mm in focal length .
Roy Halpin"s capture.