Light quality is extremely important to a photographer, just like snow for an Inuit. We have countless names for the different types of light while any average people would only call them “strong” or “weak”. The amount of light we get is very easy to measure and describe. But the quality is a far more subtle, much harder to formalize concept and therefore much more interesting to me. Modern cameras can handle low light extremely well thus photography is now possible under such difficult circumstances no one could be foreseen just until a few years before. But high sensitivity sensors with great quantum efficiency and extremely sophisticated noise reduction processing cannot create great photographs just by extending the lower bound of minimum illumination necessary to capture an image. Although these new tools certainly aid the photographing process, the quality of light (among other factors) is and always will be key to a good image.
I am currently experimenting with mainly available light, trying to find situations which work for me so I can get the results I like in a somewhat predictable manner. One of my favorite spots lately is the door of our balcony. In my opinion, this location has nearly ideal light conditions for portraits during most of the day. The balcony is relatively deep, and only the front is open (sides are solid walls), then comes the big door followed by a deep room with white walls and furniture.
This setup has a similar effect to a soft-box. Light comes through in a beautiful evenly distributed, soft way, which then decays rapidly as it penetrates into the room. A subject placed close to the door can be lit very well with a strongly directional but soft light while the background is lost in darkness.
I have taken several portraits at this place using different formats (APS-C, 35mm, 6x6cm), films and digital sensors, and a small, but representative selection can be seen in this post. I think it is interesting to see next to each other similar shoots using similar focal length but with vastly different capturing technology.
The conclusion is that, no matter what your medium is, good light (and composition) could always give respectable results but technology does not save the day if the light quality is poor for the subject. But it is again another subjective property, what is poor light for a photographer for a given purpose, could be magnificent for another. Nevertheless, I think it is crucial to study light as a photographer, amateurs and professionals alike.Many thanks for the proofreading to Ramon.