Originally posted by Tooks Yes, sorry for any confusion, the old non HSM 70-200 DG works with the current converter, but the new 70-200 HSM does not work with the converter.
In the UK, one dealer was bundling the Sigma APO 2x converter with the 70-200 HSM which was a deal put together by Sigma UK to combat the Tamron 70-200 which is considerably cheaper.
Seems to have backfired a bit though as no current Sigma Pentax fit converter works with the 70-200 HSM lens...
Sigma has released the Sony 1.4 TC HSM with, I am guessing, the Pentax model to be next, maybe in a few months.
The 1.5x Kenko and Tamron 1.4 are the only 2 TCs that I have been told to work with Pentax SDM/HSM. I have seen a Promaster 1.5 that appears to have the SDM pins inside but I do not know if IQ is any good or if it does work.
I am wait for delivery of a Kenko. I'll have to test to see if it has decent IQ.