Dale Forbes
Swarovski Optik, Austria
Here are my test with 2 adapters and vinjetting with shorter one
http://panasonicg7.blogspot.fi/
Hi Musti,
by my calculation, the length of a micro 4/3 T2 adapter should be about 35.75mm (55.0-19.25mm). Anything significantly longer or shorter than this will result in a lower image quality (especially chromatic aberration) and a large amount of refocusing between eye and camera use.
https://en.wikipedia.org/wiki/Flange_focal_distance
Happy digiscoping,
Dale