One of the main distinctions in lighting is undoubtedly that between hard and soft light. It is one of the most important parameters to consider in order to achieve the end result we have in mind. A good part of the artistic and creative possibilities available to the photographer or cinematographer is played out in this aspect. Therefore, it is imperative to know the fundamentals, on the basis of which diametrically opposed effects can also be achieved.
Direct sunlight is hard light par excellence. When it falls on a subject, it creates sharp shadows with well-defined outlines both on and behind the subject. This is therefore a very strong light, which makes every detail stand out, highlighting, for example, all the defects of a face, such as wrinkles, scars and so on.
1. Example of hard light, with sharp edges between light and shadow
With a softer light, on the contrary, we will have less sharp edges to shadows and more nuanced outlines. In the case of a face, the light will therefore smooth over defects, wrapping round the subject and making the transition from light to shadow at various points almost imperceptible.
1. Example of soft light, in which transitions from light to shadows are gradual
Distance, size and hardness
When we talk about the hardness of light, naturally we can imagine a continuum going from one extreme to the other. However, it is only the nature of the light source that has an effect here; its size and distance from the illuminated subject also contribute to the definition of transitions between light and shadow.
Take, for example, a hard light source trained on the model above, revealing details and creating sharp-edged shadows on her face. If we now bring our light source closer to the subject, we will soften the shadow projected behind, and, by moving the light source further away, we will have the opposite effect, producing a therefore much sharper shadow behind.
The size of the light source also has an obvious affect on soft and hard light. The smaller the light source, the harsher the effect, and so, if we increase its size, we can, conversely, achieve a softer lighting effect.
As for equipment, Fresnel lights or spotlights generate hard light, as they resemble a point source, while panels and softboxes project a soft light.
Diffused and bounced light
Very often, cinematographers tend to use softer lights, because this give a more natural effect. We have several options to soften lighting. One of these is to filter the light with a diffuser that spreads it in all directions. In this way, regardless of the size of the source behind the diffuser, the shadow behind the subject will be softer, as will the light falling on the subject itself. It is good to remember that if you use a filter or a diffuser in front of a light, it loses its intensity and this needs to be factored into exposure calculations (exposure compensation values are always indicated on filter and diffuser packaging).
In order to simulate soft lighting, the other approach is to bounce the light off a reflective panel or ‘bouncer’ towards the subject. This is a technique widely used by cinematographers, because the bounce light over a large surface area tends to spread the light more evenly and the illuminated surface area will be greater.
Finally, we should add that, typically, hard light has a greater range than soft light, in terms of the distance at which it can illuminate a subject. Indeed, in hard light, such as that from a Fresnel spotlight, light rays are almost parallel to each other, offering the possibility to efficiently illuminate even quite distant subjects. In the case of a soft light, from a panel or diffuser, light rays propagate in many directions, and, therefore, the lighting of the subject is optimal only at a short distance.