A shooting is a series of frames, that runs for an uninterrupted period of time. For portraits, I always prefer to use natural light because natural light is something that is freely available to all photographers. Paying more attention to constantly changing levels of natural light is the most important step to improve your photography as one must react quickly based on the amount of light available at the given time in order to produce a good photo.
Shadows are also a great way to add contrast to a photograph achieved easily by having the light source directly used for photography from the natural source i.e. sunlight. In fact there are several kinds of artificial lights – fluorescent, tungsten, LED, halogen, xenon, explosives, electric arc etc. There are also several different kinds of natural lights – sunlight, moonlight, light from other stars, fire, lightning, volcanoes, etc. Obviously, both these classes contain very different light sources. Natural light covers the huge area whereas artificial light could not even match that. The natural lights compared to the artificial light are always on and there is expenditure in that.
When photographers in general refer to hard light or soft light, they generally mean the type of shadows cast by the light. Hard light is light that falls onto the subject coming from one direction and this light does not bounce off anything else. This hard light falling on the subject results in harsh unflattering shadows. Soft light falls onto the subject from different directions or from a very large light source close to the subject. This soft light bounces off anything else before falling onto the subject making the light not very direct and harsh. This light is best for portraits as it minimizes shadows and highlights.
A bright sunny day is awful for portraits because the light from the sun casts direct light on the subject resulting in harsh shadows and could also cause the subject to squint. This is one directional light aka hard light. The only solution is to shoot in shade and to make sure that the subject is in complete shade and also to check for the sun hot spots on the background. Shooting in shade causes the shadows to disappear because now the subject is lit with soft light. One could also shoot with the sun behind the subject or shooting into the sun which creates great rim lighting on the hair. Shooting into the sun is also known as back-lighting. In this scenario, it is best to use fill in flash for two main reasons. One is that the subject will appear dark depending on the position of the sun and using flash fills in shadows which is much more appealing to the skin and has no effect on the background. The second reason is that it produces a great catch light on the eyes. One could also experiment with using the exposure compensation on the camera but even though it might expose correctly for the subject, the background will also be overexposed.
A overcast day also results in soft light illuminating the subject since clouds act as a giant diffuser in the sky. However if there is no shade and you are forced to shoot in a brightly lit open field, then one could use reflectors that will soften the hard light before it falls on to the subject.
Sunset and Sunrise photos are always emotional conveying photos which are unforgettable. Here the sun is positioned low in the sky and tends to give great portraits. Here the photographer has the option to shoot either with the sun behind them or shoot into the sun. With the sun behind the subject, this will create a really cool silhouette effect since the subject will appear dark.
It is surprising that photographers don’t pay attention, which can be improved by thinking about the light every time you snap a picture.