What is hard light?
Hard light is also called solid light in the media industry. What it's defined as is open to interpretation. You can tell by how the shadows fall. Hard lighting is very directional and cast shadows with hard edges. The softer the lighting gets, the shades become weaker and less noticeable. Harder lighting creates a lot more contrast in photographs.
Hard light vs. Soft light
There are two dominant types of lighting in photography, hard and soft. Different lighting creates different kinds of moods. A good rule of thumb for determining what kind of lighting you are using;
• Distance from the light source to the subject
• Size of the light source compared to the subject
The distance between the light source and subject makes a difference. The further the light source is, the harder the light. And vice versa, the closer, the softer. The light source's size follows a similar principle. The smaller the light, the harder, and the bigger, the softer. In short;
• Soft light: big source and close
• Hard light: small source and further
Fun example; the sun as we know it is enormous, but it's small and very far away from us. It's a hard light, creates dark shadows, and very hard to look directly at it!
Why use hard lighting?
Using hard lighting has pros and cons like everything. The lighting best suited depends on the situation. Hard lighting highlights imperfections on the skin, acne, scars, wrinkles, etc.
Also, harsh lighting can make the appearance of the skin seem white or shiny. But, hard lighting can make a person look serious and intense. That is because of the light's high contrast nature. In cinematography, it is used in action films and to portray drama, among other things.
You can play around with hard lighting. Combining it with ambient light, reflectors, bounce boards, haze, the choices are endless. Get some ideas and try something daring. Creativelive.com is a pleasant read to learn about more types of lighting.