Originally posted by yusuf This is exactly I am worried. Also, I am on k-x so no individual focus adjustment for me.
I think that was a bit of sarcasm. it is not possible for a manual lens to FF or BF unless it's user errorEDIT:
(sorry for some reason I had samyang on the brain there)
Seriously though the Sigma stuff is much better now than 10-15 years back in many cases it's better than what Pentax puts out. I would tend to buy new though because for me anyway the Sigma would have a 10 year non-transferable warranty (Canada) which has definite value
Reverse engineering a mount always will have some issues aso the warranty has value.
Like Joe I don't mid MF and would buy the Samyang. I have a couple of Samyangs on my shortlist this is one the 85 is the other (and sooner ot later the 8 in all likliehood) I have a da14 already so that fills that need