its an OK fl for portraits ... depends on what you like ... if you /3 it gives you the approx 35mm FL, so its about a 70mm on a 35 ..
it's a little more than head+shoulders. if you like a tight crop from a small distance you might look for a 254 ( 10" ) which is the "traditional" focal length for portraits. its a great focal length that gives you a little bit of distance between you and your subject too
( so you aren't all in their face ) the 10" tele optar is s sweet portrait lens, and made-for the speed graphic.
if you get the symmar, be advised you won't be able to use it converted on your camera.
its what i believe is called a plasmat design, and the focal nodes make it so the lens needs more than the named focal length ...
to focus even at infinity, and your speed doesn't have anywhere near that much stretch. it says 370, but needs way more than that ...
nice lens still, i have use and love mine ( and use it converted in a long bellows camera ) ...
good luck!
john
ps the tele optars appear on eboink from time to time in and out of shutters, not a hard lens to find.