Canon 28-90mm is a very poor lens, primarily plastic, with a plastic lens mount, and bad performance at the edges of the image. I wouldn't want to own it. The 90-300mm came in USM and non-USM versions; the USM version may be a slight improvement of your 75-300mm.
The 2x teleconverter, IF it is a Canon converter, (not Vivitar or other brand), will be the version I, not the new version II — the version II is going for $300 and I'd expect Version I to be worth maybe $150 used. It's a very good converter, but it can only be used with lens of f/2.8 or faster if you want to maintain autofocus...
That's the information I can come up with quickly :-)
R. |
