How to expose to the right
The aim with this technique is to capture the maximum amount detail and minimise the level of noise while avoiding burning out any important highlights.
This means that the exposure should be set so that the histogram is towards the right without having a large peak at the furthest point.
This can be done by taking a shot and inspecting the histogram before adjusting the exposure and taking another shot until the histogram looks correct.
You want the histogram trace to just reach the right side of the scale and not have a large peak of white pixels. If possible look at the histogram for teh colour channels to ensure none of them burn out.
Alternatively, the camera’s highlight alert can be activated to indicate when highlights are burned out, or in some cases close to being burned out.
Then instead of looking at the histogram view you can just look for the flashing that indicates that important highlights are being lost.
The trick is to find the exposure level just before this happens. In many cases reducing the exposure by 1/3EV below the value at which the critical highlights are just starting to be lost is enough.
Most compact system cameras and high-end compact cameras, as well as some DSLRs in live view mode, are capable of showing a ‘live’ histogram that displays the brightness of the scene at the selected exposure before it is shot.
Using this avoids the need for trial and error shots. You will see the peak in the histogram move as you adjust the exposure settings.