Rodenstock 360mm f6.8 Sironar-N

[Pere Casals]

I use the N 300-MC, perfect lens.

For portrait you may want a just perfect lens or a lens with particular imperfections, this is about taste.

The 360mm focal is near the same than 14", a focal very used by Yousuf Karsh for 810, IMHO that focal delivers amazing balance of perspective vs dof for that kind of portraits, the 1946 Boogie's portrait by Karsh is a master piece in that focal:

[Armin Seeholzer]

I like mine too and use the bellows just in front of the lens!