Originally posted by traderdrew
It isn't obvious to me. Why couldn't they take any Nikon lens and convert it to a K mount? I would think they would have to shave a bit off the end of the lens and slap a K mount on it.
Because I think most users would want AF on the lens if the convert it to a new mount, and then they would need electronics/software working on the new mount too. So they will not shave off anything, they will remove the old mount and take parts they have on stock for the new mount and screw that on. Then they will need replace the Nikon firmware in the lens by a Pentax version made for that lens, and then test/calibrate AF on the new mount
New Sigma lenses is designed with this in mind, so it can be done easy and cost effective.