I've had several conversations with other portrait photographers the last several years on the subject of using only ambient lighting (also known as available light) for portraits, be if family portraits, or senior portraits. Although I will shoot only ambient when the conditions are right, 99% of the time I'll use a portable strobe to accentuate my subject(s). And please don't get me wrong, I am not at all stating that shooting only available light is "wrong" or "bad". If anything, I'm just saying it's not my style, and below I'll explain why.
First what do I mean by shooting ambient? In photography, available, or ambient, light refers to any source of light that is not explicitly supplied by the photographer for the purpose of taking photographs. The available light typically refers to natural light as in the sun or moon. But it can also be artificial light from like a lamp or ceiling light fixture.
Below is a good example of using available light during a senior session I just completed last week:
In the shot above, I only used available light which in this case was the sun shining through a large window. The sun was to my right and gave this image a nice lamination to my subject. This is a great case for shooting available light.
Many people feel when shooting outside that you do not ever need, or want, to use any light source that is not natural. I’ve even had a few tell me I’m crazy when I’m shooting on an overcast day. Here is where I disagree, and here are a few reasons why. When capturing the personality of an individual I always want to capture the inner being of the individual. They say the window to the soul is a person’s eyes. When shooting outside using only ambient light (the sun) they eyes are always shaded by the upper part of the eye socket. This is what I do not want. I always want to be able to see the eyes clearly. Another reason, when shooting on an overcast day, the lighting will be very flat, and your eye will wonder around the images, rather than being drawn to your subject. As a photographer I do not want your eyes circling around the photograph. I want your eye to be directed to my subject.
Here are a couple of samples of what I'm talking about:
This image was taken during a winter session for one of my 2013 seniors Madi. In this example you’ll notice that your eye is drawn to the right eye of Madi. It’s not wondering around looking at the background. You’ll also notice that there is a nice gentle falling off of the light. This falling off of the light gives the image depth, as well as warmth. It was shot with one portable strobe being located camera left about 40 degrees.
Now compare that with a test shot I took of my oldest son using only available light:
This shot was taken on an overcast day which gives you very even light. The image is rather flat, and you’ll notice the eyes are shaded. And I think you’ll also notice your eye is very busy looking around his face and does not really rest in any one area. This is not what a photographer wants to happen. Our goal is to direct the eye to the subject and have it rest there.