great issue with this

hello to everybody!

i just bought an AF teleconv branded Sigma....it's very rare and I cannot find nowhere info about it, no review...no info at all...also in Sigma website.

here the photo...is identical!

https://www.pentaxuser.com/forum/topic/sigma-af-1-4x-tele-converter-for-pentax-r...

Anybody own it?is it compatible with all lens (I own some pentax and some Tamron)?

I'm really worried about mechanical compatibility
thank you to all will help me
Regards

Looks like the one Daz was advertising a while back LINK

yeah...is completely the same...

I sent to him a message...probably he can help me.

If any other have experience with it, would be very usefull and kind.

Looks like the usual older 1.4x converter ... screw drive only so won't work with Pentax SDM or Sigma HSM lenses. Non reporting so your exif will only show as if the converter wasn't there and you may have to apply a little -EV.

I see...I was sure that is not working with SDM...I could not see the contact..

I'm wondering about mechanical problems too....as I know that some Sigma Teleconv have protruding elements that can damage the lens.

I really DO NOT understand SIGMA that release teleconv. that cannot match with their own lens too!!

From the look of it I would say this is quite an old teleconverter as it doesn't have the protruding front element and is probably pre-HSM. You shouldn't have any mechanical problems with it.

Even Sigma's newest teleconverter doesn't work with HSM lenses although this only applies to Pentax mount, the Canon/Nikon/Sony variants work fine on all their compatible lenses.

i didn't know!

As usual...Pentax discrimination...hihihhiih

I don't think it's discrimination so much as lack of technical knowledge.
Sigma don't pay a licence fee to any of the camera makers and reverse engineer the lens mounts. Pentax mount is apparently a lot more complicated than the others (especially SDM)

I've replied to your PM about this Teleconverter, which used to belong to me. There are no mechanical issues with it, but Mike-P is correct when he says it will not work with SDM or HSM lenses. The glass is good and it takes sharp photos. I sold it when I bought my Pentax 1.4 TC, which is in another league altogether.

Regards
David

The TC in the thread shown, is the one David is talking about above.

It has no HSM/SDM contacts. It works perfectly with all my screw drive glass, no problems at all. It works as you would want on my Tamron 70-200.
Hope this helps.

now...the situation is clear, thanks for your explanation and report.
helps a lot.
thanks to all and have nice pics too
regards