Reposted question from LHanson on the Forum:
In your opinion what is the best most cost efficient lens for portraits?
Hello LHanson! Thanks for writing on the forums.
85mm is widely considered to be ideal (most flattering) length for portraits. If you’re on an APS-C sensor, you multiply your millimeters by 1.6 for Canon and 1.5 for Nikon. So a 50mm lens turns into an 80mm on a Canon. And you can’t get more cost effective than the nifty fifty fantastic plastic Canon 50mm f/1.8, around $100 new, $75 used. Nikon also has a similarly priced 50mm f/1.8.
That said, I plopped more money down for the Canon 50mm f/1.4, $400. It was just made better. Has a larger focus ring for manual focus. Focused more silently (USM motor). And has a metal mount.
Then there’s the Canon 85mm f/1.8, $420 new $340 used. Definitely one to own if you’re on a full-frame sensor. On a crop it’s effectively 136mm. You’d better have plenty of backup room (on a prime lens the zoom is your feet).
So the used 50mm f/1.8 is the winner for a sharp, economical portrait lens.