Originally posted by jbrowning Have you tried the Pentax teleconverter with the Sigma 70-200 f/2.8 or the Sigma 50-500?
Those are about the only other lenses I use anymore.
Thanks
Jim
It depends which Sigmas your talking about
The HD converter will work well with all screw drive Sigmas but Sigma HSM reverse engineering is flaky
the Sigma 70-200 f2.8 EX OS wil not focus well with the HD converter
For the HSM Bigma you need others to respond.
Sigmas I have and tried the HD converter with
Sigma 400 Telemacro = good
Sigma Bigma EX = good
Sigma 70-200 EX = good
Sigma 70-200 EX os = unusable
IMO the HD converter is considerably better value as an in lens converter than the Pz tamron/teleplus etc it works
I bought my Pz 1.4 and 2.0 converters years ago and paid £32 and £8 respective about what they're worth .!
I paid £379 for my HD converter and again feel I got value.
If you want/need to drive in lens Pentax lens in AF with a converter and have full SR etc then don't throw any money on the non functional Pz legacy converters.