My 'regular' paintings and drawings, ie: the ones I typically send to the galleries and put up on my website, are usually done from photographs out of financial necessity and time constraints. However, I regularly work from life, which really helps and improves my work from photographs. When I paint or draw from life, I am really engaged in looking at my subject, and learning about their shape, proportions, form, musculature, etc. It is at once more challenging and easier, since all the information is right there in front of me, untranslated. This is more difficult because I have to organize the information on my own, and there are the issues of the model's movement (even if just breathing!) and binocular vision and my own movement to contend with. But I never run in to the problem of fighting with the color or value in front of me, like I sometimes do when working from photography.
The model in the drawing above was a delight to work with. She chose a very dynamic and interesting pose, and she smiled the whole evening! It's nice to work with a model who seems to enjoy herself. The model in the portrait painting was not as pouty as I made her... I haven't painted a portrait from life in some time, so I'm a little rusty. I will get one more chance with this portrait this week.
I absolutely treasure my time drawing and painting from live models. There's something extremely rewarding about it, even when the resultant work isn't great.