Part 3 Lesson 4: FILL LIGHT
Using 2 lights, even when you only have one
So far we've assumed you're dealing with a single source of light - the sun, a torch, a desklamp. But you will have more options if you have more than one source of light. The disadvantage of having a strong light coming from a single direction - hard shadows and high contrast - can be overcome if you have a second light.
Photographers working in studios can set up as many lights as they want. They can angle them, turn them up or down, make them hard or soft. I'm assuming you're just working with natural daylight though, and maybe a flash.
You can get a lot of the benefits available to studio photographers with no need for new kit if you appreciate the fact that a second light source doesn't have to be an entirely new light - it can simply be the original light source, but reflected
In this email I'll explain how to use a reflector as a second light source to create a fill light which will soften hard shadows.
What is a fill light?
If you have one particularly strong light source (the midday sun for example), it will throw correspondingly strong shadows. This results in what's called a high dynamic range ("HDR") in your photograph - you have a very bright side of your image on the side of the sun, and a very dark opposite side.
In this example the sunlight is coming from the left and the focal point of the flower is deep in shadow:
The solution is to reduce the dynamic range (on your subject at least) by brightening the shadows. You do this by shining a second light source into the shadows. The technical term for this is "fill light", but as I explained above, it doesn't have to be an actual light. You can get this effect just by reflecting the sunlight back into the shadows:
In this image the light was simply reflected back into the flower by using a piece of white 5mm foamcore:
The HDR problem is caused because your camera's sensor has a dynamic range which is smaller than the eye's. It can't fit both the darks and the brights in the same image. The result is that you lose all the information at one end of the dynamic range, and end up with blocky black shadows, or blown out highlights. By using a fill light, you reduce the dynamic range of the whole image.
THIS WEEK'S PROJECT
Take 2 photos
First photo: in a place where you have strong directional light (bright sunlight, or very close to a desk lamp), take a photo and take note of the strong shadows.
Second photo: repeat the first photo, but with a white reflector opposite the light source, to soften the shadows.
Bonus photos: try holding the reflector closer and further away. Try using aluminium foil, or a mirror as a reflector. Notice what happens to the shadows in each case.
If you want to catch up on previous lessons, or just like to have a book in your hands, you will enjoy using the A Year With My Camera workbooks. Designed to be written in, they will give you a complete record of your whole year. Search on your local Amazon store.