My new camera lens is a World fastest telelens, Canon EF 200mm f1.8L.
Images with this Lens: http://astroanarchy.blogspot.com/search/label/Canon%20200mm%20f1.8%20images
Here is some information: http://www.mir.com.my/rb/photography/hardwares/classics/eos/EF-lenses/EF200mmf18LUSM/index.htm
This lens has best difraction limited optical quality I have seen.
Lens is used in SuperWASP project, actually eight of them: http://www.superwasp.org/
The model I bought is electronically focused, so there is no mechanical link between lenses and
focusin ring. After lots of thinking I ended up to modify the lens for the astro work.
Opening up and messing with electronic and mechanic of the expencive lens was not a
easy decision, but it was the only way to use it with my new astrocamera, QHY9.