Kenko 36mm and Canon 400mm F5.6
I have been searching for a bit for information regarding the maximum obtainable magnification with the combination of Kenko 36mm Extension Tube and Canon 400mm F5.6.
The closest I've come is a blog stating that with the Kenko 36mm, that the 400mm focuses to about 6 feet, see URL:
http://blog.theeyegame.com/2010/05/0...forgotten-400/
I have a Canon 25 mm extension tube which achieves 0.21x magnification at 7 feet, but would like to potentially use the Kenko 36 mm, but for it to be worthwhile I think I need to get around 0.34x or more at 6 feet.
Has anyone here obtained the magnification at the closest focus for this pairing? (Unfortunately Kenko's own website does not provide the nice tabulation like Canon does for their extenders)