I just came across these photos. They are around 15 years old. I walked about town with my lovely friend Bettina, and took her portrait in various settings. I used a medium telephoto lens (135 mm I think), and a ISO 125 film (I used a high-sharpness developer and if I used a faster film, the grain would be enormous). So I had to use a tripod, logging it about all over, setting up, adjusting.
If it was now, I would use one of the new generation digital SLRs, a setting of ISO 1600 or perhaps even 3200, and a image-stabilizing zoom lens, and I would not need a tripod no matter how deep in the woods we were. And I would get better sharpness yet*. Again, gotta love that.
* OK, sharpness is not the most critical thing in portraits, but you need a certain minimum. And you can always subtract it, but not add it.