This is a rev1 of my extension ring set for the Canon EF mount.
This part is designed to be printable without any support material. A well adjusted printer is necessary fo a tight fit.
Extension tubes are mainly used to reduce the focus distance of a lens for macro photo.
Better fit, locking, texture and electrical contacts are planned for later versions.
The sample photos are taken with a Canon 550D (T2i), a 70-200 F/4 USM and a total of 100mm extension (2x this part)
Please leave feedback, photos and the like in the comments! :)
Amplivibe did what i newer got around to do and remixed this to different lengths at http://www.thingiverse.com/thing:334254