>>2955167Your a6000 has an APS-C sensor, so your Takumar will have about the field of view of a 75mm lens on film. Which is short telephoto, pretty close to the classic head-and-shoulders portrait focal length of 85mm. You will have to back up to get a whole person in the frame, if you wanna do that your 28 might work better.
Also, check if your Takumar is the eight-element variant. (
http://www.pentaxforums.com/lensreviews/Super-Takumar-50mm-F1.4-Early.html) The early models are eight-element, later ones are seven-element. There's almost no optical difference, but the eight-element ones sell for more because of collectors.
Here's your Makinon, if your interested.
http://www.pentaxforums.com/userreviews/makinon-28mm-f2-8-auto.html 