Tamron SP Adaptall-2 28-80mm f3.5-4.2 27A Mini Review

I got this lens when I was eying for one of the PKA mount on eBay. It's a SP lens which interestingly requires ring twist mechanism to zoom instead of a push-pull mechanism which is the common zooming practice.

The 28-80mm f3.5-4.2 lens is the one on the right. The left one is the Tamron 90mm f2.5 52BB lens.

Optically however, I find this lens to be rather disappointing. Wide open it is very soft and I find it hard to believe that they actually named the lens an SP. It sharpens up well by f8, but so does my kit lens. So I sold then lens pretty quickly as it's really not a very useful lens for me. 

Here is the original article which this mini review came from.