Much Ado About Nothing: White/White, Black/Black. It's all GREY.

So our task for Week 2 was to expose our cameras' propensity for turning things grey. You see the camera doesn't understand exactly what it is you're shooting, and as a result is set to average a scene to 18% grey. This is all to do with metering and exposure, and is why snow scenes are likely to turn out a dull grey instead of a bright white.

The task set was to shoot the following:

1. White object against white background
2. Black object against black background

The first shot was to be taken using aperture priority. Seeing as the scenes were at a fairly uniform brightness I left the metering mode on evaluative (the standard mode). All shots were taken with AWB (as DS says, when shooting in RAW you can change this in processing later, so keep it simple) at ISO 400.

f/1.8, 1/2500

The picture looks grey because the camera has underexposed the image, having metered the scene and deciding it was too bright based on it's averaging to grey rule. In order to counteract this you need to overexpose the image by 1-2 stops compared to what your camera has decided, so I did this by switching to manual mode and reducing the shutter speed, with the following results:

f/1.8, 1/1250 (+1 stop)

f/1.8, 1/640 (+ 2 stops)

f/1.8, 1/800 (somewhere between +1 & 2 stops)

I felt when reviewing the image on the camera that the +2 stops was slightly overexposed, so I reigned it in a little. But I think the series very clearly shows that the camera's automatic metering doesn't always get it right, so it's important be aware of how it works and what it's limitations are so that you can apply the necessary adjustments to get the right image.

The next series illustrates the same principle but in reverse: when faced with a predominantly black scene the camera will try to average it to grey, and it will do this by overexposing the shot. This time the solution is to underexpose by 1-2 stops.