My First webcam was a c9000... and it does have good resolution, when new, and good distance focus.... 2mp at 1600x1200 max size. The third year definition went down some. Hubble doesn't necessarily improve an already sharp camera, and the 9000 was excellent. Mine's still up after 5 years, and worked last week when I checked it... but I no longer use it actively.
About all a Hubble fix does for a well operating 9000 is a degree of 'fisheye'. It is a standard definition cam 4:3 ...
Where the Hubble works best is on some of the newer models, like the C920 and C910. The lower number cams from Logitech vary in Pixels and results. Also there is little or no effect noticed
with most IP cams, for some reason. Now, I've a C910 with a -3 overlay to expand the field a few degrees, and one with a -2. My other three active cams are c920s with -2 correction. All of them have a distinct focus improvement at distance when properly adjusted. Remember also, just on the odd chance, we are talking 'negative' diopter... a 'positive' diopter won't do a thing to help.
There are several C9000 with Hubble here :
http://ourspecial.net/twinhollies/weathercenter/campage/