Originally posted by fgpinarli Does it mean that the cheap adapter has a better conductivity than the Pentax one?
The genuine Pentax adapter has no flange on it and does not touch the contacts at all. Takumar lenses usually have non-conductive mounts on them and are typically a smaller diameter that does not touch the contacts either. What some people do is after mounting the lens they stuff some metal foil between the lens and the contacts. You could try making a collar of sorts from an aluminum beverage can. Just be sure to sand off any paint or coatings on the area that will touch the contacts. The insides of the cans have a clear coating on them. The can material may be thick enough to throw off infinity focus though.