Here's one for the camera lens gurus.
If you had $1000 to spend and you decided on a widefield lens for astrophotography to be used with either a Canon DSLR or a dedicated CCD with T thread adapter,
what would you choose and why? Excluding the famous 50mm f/1.8 Canon lens. I already know it is a must have
Maybe something less than this focal length or more than this focal length.