Tamron 2x Teleconverter

Hi, does anyone have any experience with the Tamron 2x teleconverter on the Canon 70-200mm f2.8 IS .With the two stop loss I was wondering about IQ and AF Thanks,Alan

Anybody? Has anybody used a Tamron 2x teleconverter on any lens other than the 70-200?
Alan

The IQ is still decent to about 275mm(give or take a bit) but If you zoom much farther the IQ goes to he**. Kind of defeats the point of the TC . The AF becomes very slow, at least as slow as my non-hsm/usm lenses. That being said, I have shot a number of football games with the combo. I did get a higher than usual number of slightly oof shots and obviously they were soft and had quite a bit of CA (especially on the long end). In addition, even when the subject is in focus the background oof areas look horrible. I was able to use some of the shots (they only had to be newsprint quality) but for anything else I have given up on the combo, and would advise against it.
-Trevor

Green_Tea wrote in post #8916319
The IQ is still decent to about 275mm(give or take a bit) but If you zoom much farther the IQ goes to he**. Kind of defeats the point of the TC . The AF becomes very slow, at least as slow as my non-hsm/usm lenses. That being said, I have shot a number of football games with the combo. I did get a higher than usual number of slightly oof shots and obviously they were soft and had quite a bit of CA (especially on the long end). In addition, even when the subject is in focus the background oof areas look horrible. I was able to use some of the shots (they only had to be newsprint quality) but for anything else I have given up on the combo, and would advise against it.
-Trevor

Thank you Trevor I'll think I will just stick with using my Kenko 1.4 that I used with my 70-200 f4 Thanks again

Alan

I dunno about the 70-200 F/2.8 as I've only briefly played with one, but the Tamron 2x TC (assuming it's one of their better versions) can certainly deliver cracking results if the lens is up to it.

Despite the common belief that they're no good on shorter focal lens, I use mine on a mid-range zoom. I also use it on the 400 a bit if I'm prepared for the tiny aperture and MF.