My idea is sort of game where someone has an problem on the subject of portrait lighting or a question about how a certain photo is made posts an example photo and I'll have a look and see if that can be reproduced at least in diagram form and perhaps even give some advice if Im able. That diagram or the piece of advice is of course open to discussion as this thread is not merely for my curiosity(well maybe 75% of it is) to see if I can figure things out from images posted in any meaningful manner. Gear does matter but mostly in modifiers and in most of the cases the brand means nothing. My personal toolbox consists of range of studio flashes, battery flashes and dirt cheap speedlites combined in a wide variety of modifiers.
I have a studio at my disposal but limited time to do anything non commercial so I'll see if I could arrange a day for turning a bunch of diagrams into reality if this picks up. (I suppose this is basically an AMA -thread)
For an example(This is not meant to be a thread just for copying another artist's photo but this was the only example I had at my disposal that had the inspiration easily to be found): A couple of years back I was approached by an younger gentleman on the subject of getting a photo of himself in the same manner as the posthumous painting of Kennedy.
John Fitzgerald Kennedy by Aaron Shikler
Painting itself is quite forgiving as there's clearly only one light source but coming from an hard source from high angle from behind and broad side translating to something like this:
From top to bottom:
Silver reflecting umbrella as keylight and spill for background from around 2,5m high
Silver reflecting umbrella continuing the keylight from around 1,5m high
150cm softbox for fill light the center at chest height
Power ratios between flash units went something like 1:1, 1:2, 1:8
Reproducing the exact lighting in the painting could have been possible with one light if the keylight had been about twice as high but managing the shadows in photo would have been too troublesome given the space restrictions at the time. I chose umbrellas as keylight for the hard quality of the light and for the much forgiving spill which suited for this kind of setup. Large fill light just to pull those shadows up, nothing more. The location and the angle of the fill prevent the shadows turning too flat and dual light source feel.
The diagram translated to this in real world
I'm in no way and authority on the subject of portrait photography and lighting but I feel that through my work in the field I've accumulated knowledge exceeding that of an average hobbyist's.