Apropos skylights and appropriate lighting for studio.
Natural light features VARIABILITY and EVENNESS.
There is VARIABILITY in COLOR temperature and BRIGHTNESS from AM to PM.
Proper skylight positioning allows EVEN ILLUMINATION in the space.
1.) Opening should face north to receive REFLECTED light.
2.) Steep or vertical light to avoid high sun slanting in.
3.) Early morning, high noon, and evening provide very different lighting conditions.
4.) Make your painting look good in each of these periods and it will look good in ANY lighting.
5.) Don't underestimate the value of observing your work in the dim light of early and late times of the day.
6.) Use artificial lighting as an alternate source to extend working hours.
7.) Artificial lighting offers one temperature and one brightness without variability.
It is neither the color temperature, nor the brightness which is most valuable to me but rather it is the variability of the light I find most useful. Plein Air painters who work outdoors in early morning, high noon and evening will know the same phenomenon but use it on three or four different paintings, one for each period.