Can I replace my 100-400 with a 70-200 + 1.4 TC?

[desantnik]

These are all taken on the 1DMK2n. In fairness, I do believe it's entirely possible to get a bad copy of the lens which is probably why it gets such mixed reviews. :shrug:

I've often wondered is it a "bad copy" of the lens or the camera or whether not not there is a mismatch between the two.

My 350D with the L 300mm F4 worked a treat but my new 30D doesn't work too well with the 300mm.

A friend suggested there is an element of "tuning up" or "matching" that a service centre can do and that such problems we've talked about in this thread (and my example above) are down to such things...