Let’s talk about quality of light in more depth. To quickly recap, when we talk about quality, we simply mean, is the light soft or hard?
There are no rules about what quality of light to use where, but there are guidelines and accepted principles. Hard light suits grittier subjects as it shows off texture and shape. Softer light is more flattering. Don’t forget, you can play around with these as much as you like. No-one says you always have to photograph the same subjects the same way.
Size matters. A light source that is large in relation to the subject, will create a soft light, and something that is small in relation to the subject will create a hard light. Size matters because of how light travels from the source to the subject. Light can only travel in straight lines. Therefore, the sides of an object/subject that don’t directly face the light source will be in transition from highlight to shadow, or even in full shadow if they’re facing the opposite way
One of the easiest ways to picture this, is to imagine yourself as the subject. In your mind, face the light source, and picture how much light will be falling on you. Now turn your head, and you’ll be able to appreciate how the light fades away until eventually it’s directly behind you. Imagine this with both a small light source, where the transition from light to dark will be very dramatic, and with a larger source, where you’ll be able to see the light source for longer as you turn away. The longer you can see the light source for as you rotate, the more the light is wrapping round you, creating a more gradual transition from highlight to shadow.
A hard light source will have a dramatic transition from highlight to shadow, and will cast shadows that have a clear outline. A soft light source will have a more gradual transition from highlight to shadow, and will cast shadows with a more diffuse edge, rather than a sharp outline.
I mentioned earlier the phrase “In relation to the subject” when I talked about size. This matters because the same light source will alter it’s quality, depending on how big it is in relation to the subject. The perfect example is the Sun. If you imagine the light the Sun casts on a cloudless day it’s definitely “Hard”. There is a very dramatic transition from highlight to shadow, and the cast shadows are very crisp. So the Sun is obviously a small source. Well, actually, no. The Sun is in fact absolutely enormous, but it’s so far away from us (thankfully) that in relation to us, it’s tiny, therefore casts a hard light.
By the same token, you can buy yourself an expensive modifier like a beauty dish or softbox, and think to yourself “This will give me a lovely soft light”. Then you wonder why you’re getting hard edged shadows when you place the light 20 feet from your subject. A modifier like a softbox will only be “soft” if it’s large in relation to the subject, so if it’s very far away (besides the obvious quantity issues of less light getting to the subject) it will now be small in relation to the subject, and therefore casting a harder light.
Quality of Light – Modifiers
There’s a whole world of “modifiers” out there – tools you can buy to add to your lights that change the quality of the light. They range in price from a few pounds, up to thousands, and can be bought for flashguns, flash heads, tungsten lights, LED panels, you name it, you can buy a modifier for it.
Essentially though, no matter what modifier you’re using, all it will be doing is making the light you started with softer or harder. There are an almost infinite number of points on the curve between something which is a pure “point” source of light and very hard, through to the ultimate softness of an overcast day. The various modifiers you can buy simply fit themselves somewhere on this curve between soft and hard.
Any modifier will also of course have other trade-offs – ranging from price and build quality to things like portability and compatibility. I’ll be covering some of the most common types of modifiers you’ll encounter later in the course, but for now all you need to know is that basic truth that they just make light harder or softer, and there’s often no need to go and spend a fortune on the latest and greatest!