2. Set your camera to manual mode. Now you can see your light meter! The mid-tone exposure is indicated by the ‘0’ on the meter scale with darker or lighter exposures as – or + on either side. Repeat the exercise in manual mode, this time adjusting either your aperture or shutter to place the dark, mid and light tones at their correct positions on the histogram. The light and dark tones shouldn’t fall off either the left or right side of the graph. Add the shots to your learning log with sketches of their histograms and your observations.
Switching to manual mode disconnects the aperture, shutter and ISO so they’re no longer linked. Because they’re no longer reciprocal, you can make adjustments to any one of them without affecting the others.
For this exercise I happened to get the correct ‘black’ shot when I adjusted from auto to manual so I had a good starting point, I only had to adjust the aperture to get the correct balance on the grey and this also worked for getting the correct white tone although for the white I did also have to adjust the exposure compensation to +3.