In message ,
wrote:

Kibo informs me that "Don" stated that:

Folks

I have been trying to use the Tamron SP AF TeleConvertor 300F-CA 2X with my
400 F5.6 L series lens but the results are dismal. I obviously was aware I
would have to manual focus but I haven't been able to get a sharp shot or
even a keeper for that matter yet. Any one has any ideas or similar
experience or would care to comment and assist me if I am doing something
wrong. I have tried from F11 to F14 on tripod etc.

I also have a 10D, & I've found it impossible to get a good manual focus
in general, due to fuzziness of the & lack of focussing aids on the
viewfinder. I'm guessing that you're running into the same problem.

Whenever tuning anything where the ideal position doesn't snap and
sparkle, I find the best approach is to feel the amount of rotation (or
# of clicks) from where it gets noticeably bad in each direction, and
then rotate (or click) half that much back towards the middle. I do
this for tracking VCRs, tuning radios, manual focusing, etc.
--


John P Sheehy