This is a good fixed focal length lens; star testing shows that a good
behaviour can be obtained with a couple of stopping down. Testing was
made on a clear and cold night of
December 2010, with automatic tracking of my Kenko NES mount. Exposures
and ISO were selected to maintain a constant nominal exposure, except
the two higher apertures.
The results show that a good star shape is obtained at f/4.
Thanks to Alessandro Gambaro for testing together his objective.
Aperture testing with Canon EOS 5D (full
frame)
Click on the image for the full-res
version (200% of original resolution)
Focus testing with Canon EOS 5D (full
frame)
Click on the image for the full-res
version (200% of original resolution)