Find a strong, definite colour and choose a viewpoint so that the colour fills the viewfinder frame. Find the average exposure setting. Then take a sequence of pictures; all composed exactly the same, but differently exposed from bright to dark by adjusting the aperture setting.
Canon EOS 650D with EF 18-200mm f/3.5 lens.
I chose a red scatter cushion against red upholstery. The over-exposed shots, especially the +1.0EV, render the red rather bright, almost pink-like. As the exposure was changed the colour became more saturated, as expected. Also, in the under-exposed shots the detail and texture in the material becomes more visible. In my opinion the slightly under-exposed one (–0.5EV) most closely matched how my eyes saw the colour in real life, which goes to show that the camera’s metering isn’t always perfect.
What I’ve learned:
It’s possible to control the strength of a colour through a deliberate choice of exposure. This is something I’ve usually left to post-processing, often boosting saturation if I think the camera didn’t quite catch the colours well enough. What this exercise has taught me is that to a certain extent I can actually do this in camera. Very interesting.