A-Mount Teleconverters Guide

There is comparison Tamron AF 1.4x TC and Kenko Teleplus Pro 300 here
Test was done with Tamron 100-400 lens in Canon mount.

There are also sample pictures of:
Sigma 10-20/4-5.6 EX DC HSM vs. Canon 10-22/3.5-4.5 USM
Sigma 24-70/2.8 EX DG Macro vs. Canon 24-70/2.8 L USM
Sigma 30/1.4 EX DC HSM

Rambler358 wrote: Some really great info here! I've just recently acquired a rare Tokina AT-X 340 AF II 100-300mm f/4 lens and was looking for a good 2x TC. From what's stated above, and since this is a constant f/4 lens I should be able to use a 2x TC. However, Tokina's website states the following for their Kenko PRO 300 2.0x TC: "Full AF operation with PRO 300 2.0x is possible when using camera lenses with maximum aperture of F2.8 or brighter." So now I'm a little confused - can anyone shed some light if I'll in fact be able to use a 2x TC and still have AF? Or will I need to drop down to a 1.4x TC in order to retain AF? Many thanks in advance!

The Pro 300 2X will AF with your 100-300/4 lens since it will AF with a 70-210/4 lens. Since the effective aperture is F8, AF will only work in good light and subject with high contrast.
Hope this help.
eccl

I believe 200/4 was mentioned in the TC guide:

"Minolta APO teleconverters are designed specifically for certain Minolta lenses only, all of the Minolta AF Telephoto G lenses such as 135/2.8 STF, 200/2.8, 300/2.8, 300/2.8 SSM, 300/4, 400/4.5, 600/4, 200/4, 70-200/2.8 SSM. "

Regards,
eccl

Are you using a tripod or at least monopod with your 300/2.8 + APO 2X combination? Handheld is alrady difficult for 300/2.8, add a 2X it will be even tougher. You'll need a HEAVY DUTY tripod with a good ball head or heavy duty head. Mount the lens onto the tripod instead of the camera as you don't want the camera (mount) to support the weight of the heavy lens.

Picture quality will be degraded with a 2X TC but the result should not be too bad (at least 70-75% of original).

Hope this help.
eccl

Edited by eccl - 18 March 2006 at 23:50

Hi all,

i would know your opinion on the use of a kenko Teleplus 300 1,4x with a sigma 135-400 4,5/5,6 ?

I think i'll lost AF (maybe can i keep it by hidding 3 pins ?) but what about the image quality ?

What is your opinion on this ?
Thanks,
Anthony

eccl, thanks very much for a very informative posting (especially for those of us new to the Minolta world).

One small question for you or anybody else that can help me: on the Minolta Yahoo! group, I found out about the Canon FD lens adaptor which would be perfect for me and you've alluded to it as well. However, the only link I've been given for actually acquiring such an adapter has been to BHPhoto in the US. I was wondering if anybody knows where in the UK one might get such an adaptor as the shipping charge from the US is as much as the adaptor itself.

cheers,
eric

PS - Link to BHPhoto product page

Thanks eccl. My findings so far have been that there does not seem to be anybody in the UK that deals with such. BHPhoto it will have to be. I guess the shipping costs are not that bad...

eric