|
Pat, if you get a chance to ask him, that would be appreciated. All I really want to know is if the 90mm lens might be perhaps an ED style rather than a basic achromatic. The reason I am curious is that the " no name" York refractor seems to be almost as sharp and as free of chromatic aberration as my Sky Watcher ED 80. Of course, being an f/10, the colour aberration should not be as pronounced as a short focal length?? Maybe?? Thanks, Stewart
|