Here's seven portrait studies I did in Ignat Ignatov's alla prima portrait painting class.
Each portrait was painted in 5 hours in one session with small breaks for the model of course and one half hour for lunch.
The lighting in the rooms at the Los Angeles Academy Of Figurative Art is from skylights and Ignat also supplemented this light with artificial light sources sometimes coming from other directions. These lighting problems were somewhat advanced so it would be a good idea that you have some solid drawing skills before taking his class.
I really enjoyed working with Ignat. He suggested we start by drawing or painting a monochrome sketch of the big masses and value relationships before putting the color in. I found it a refreshing educational shot in the arm and I learned a lot. Ignat would make suggestions occasionally and they were always right on. He never worked on my pictures directly but would point out where I miscalculated a value or color or where I had a drawing error.
If your ever in Southern California and would like to take an informative workshop with plenty of demos as well, I highly recommend Ignats workshop at the Los Angeles Academy Of Figurative Art.