Pentax Lens Adapter question

[T.W.]

Hello, I am looking for some help on a lens adapter.

I was wondering if a Pentax T-mount adapter would be compatible with the Sigma 50-500mm f/4-6.3 EX APO DG (Made for Canon cameras). Is it possible to just put a Pentax T-Mount adapter on the Canon lens and still be effective as before? Also, will it work with a 2x teleconverter designed for Canon?

Thank you.

[CptOfGondor]

No, you cannot adapter Canon EF Mount lenses to Pentax K. the focal distance for Canon is shorter thatn Pentax.

Btw, Sigma didn't design the Bigma with Pentax in mind. It really just for AF. I tested one at the store and the manual focus ring didn't even respond. (It was a used one) but either way, don't waste your $1000 to buy a 50-500 for pentax. Its damn heavy and slow.

If you have $1000 to blow, why not just get a 70-200 f2.8 or whatever?