AF teleconverters

Has Pentax released a 2x teleconverter that is compatible with AF lenses ? There's a Sigma one, but is there a Pentax one ...

No.
There is an 1.7 one though.
Also there is a very good Kenko AF-Konverter 2x DG MC 7.

I think the 1.7 is an AF converter for MF lenses......and not a proper teleconverter....

I'm sure someone will put me right

The Pentax 1.7x AF converter can be used to convert manual focus lenses to autofocus.

However, you can just as easily use it with an autofocus lens - to some advantage! Because the focus is entirely inside the AF1.7x the lens never moves. You just manually set a rough position (say infinity) and the converter will do the rest.

In practise it works extremely well - I've used it with the SMC-F 70-210 and the SMC-FA 80-320

Matt

One general problem with converters which wire all contacts is that you cannot set the correct (doubled) focal width for SR.

Not a problem with the Pentax one
The body has absolutely no idea of the focal length - you have to manually enter it (which is a pain to work out 1.7x in your head).

Only snag is that it won't work so well for zooming...

Matt

I really hope they put a manual override into the next firmware update, the teleconverter SR issue is really going to annoy me.

With the 1.5 multiplier, tele-converters aren't quite so attractive as they were on film bodies.

G

without SR they certainly aren't

I did a few tests with a Pentax 1.7X and Sigma 2Z, my observations were posted in this thread...
https://www.pentaxuser.com/forum/viewtopic.php?t=3742

I'm feeling slow today, SR is what ?

Shake reduction