Sunny days are a bit of a trap. It might seem like a good idea to photograph people in bright sunshine, but the dynamic range - i.e. the difference between bright and dark areas of your image, will be too great for the camera to capture. Stops or EV's (Exposure Values), are each either a doubling of halving of light intensity, they are the common currency of exposure and appear in Shutter Speeds, Aperture and ISO values. While we can see between 20 and 24 Stops (human sight varies quite considerably), most cameras can barely deal with more than 13.
There are several possible solutions:
1. If exposing for the whole scene with Evaluative metering, which is the default mode of most Canon cameras, pop up the flash and use it to fill in the light onto your subject - thus reducing the DR. Alternatively, use a white coloured material - even white paper, to form a reflector to direct some light onto them and thus reduce shadow and thus the dynamic range.
2. If that is not practical or desirable, move your subjects into shadowed areas - within the shadow of structures or trees, for example. That will also stop them from squinting in the bright light, and they can take off any sunglasses. This is my preferred method. I use spot focus and spot metering, with both assigned to back buttons. This again reduces the DR but this time by moving the light on the subjects closer to that of the surrounds.
The extreme example of this is to have a very dark background and expose for their faces.
In the following examples, the first picture is of several taken of a couple wanted a casual photo of them on a ferry trip on a really, really bright day, so I placed them in a shaded area of the boat that still allowed some indication of being on a ferry on a sunny day. Even so, there was obvious shade on their faces, but that echoes the actual conditions without blowing out the exposure on the background or under-exposing their faces. (BTW, there was no colour imbalance, they were both quite burnt from being in Auckland's brutal sun the day before!). I didn't actually use this one because the male had his sun glasses on.
In essence, what I have tried to do is reduce the degree of dynamic range between my subjects and the background, by reducing the light levels in which they are located, and then metering for them within that context.
In the second image of a Canadian First Nations dancer, I positioned myself so that there was a black backdrop behind him, and used spot focus on his eyes, and spot metering on his face to get the exposure right. The black background really made him stand out - again BB Focus and Metering. Thus, I have made the subject by far the brightest element in the image and shot to make that element correctly exposed and letting the background go to black, or just very dark. We still know the subject is in bright light, but that environmental element no longer dominates the scene - the subject does.
I used a similar technique for this Māori dancer, I wanted the dramatic contrast to highlight her striking looks and dignity. It was just on midday in high summer, so the contrast was really brutal - arguably the worst conditions possible, but that was when the performance was scheduled so I had to work with it. The location was in the forecourt of the Auckland Art Gallery. By allowing the background, which was in deep shade, to be underexposed to almost black, it made her really pop and provided a dramatic contrast with the black costume and silver highlights. So, again I used spot focus on her eyes, and spot metering on her face, and let the background go to black.
Other references: Videos by Sean Tucker:
