If lighting is flat, portraits (of light-haired people?) can be underexposed and push processed to give greater contrast between different parts of the skin.
I tried it with a modern film, the flat curve Fuji Acros, developed in Fomadon Excel (similar to Xtol, just happened to have this).
2 studio lights close to the photographer were used. Exposure was incident light on the model via a reliable flash meter.
(1) Normally exposed and developed.
(2) Underexposed 1 stop, developed 40% longer.
(3) Underexposed 1 stop, developed 40 minutes, agitated every 10 min -this is complete development, called gamma infinity.
Attachments are inverted negative scans, black/white points set, sharpened equally, resized, no other changes.
I wonder if there are any comments on underexposing and overdeveloping portraits, thanks.