The Lastolite Xpobalance enables digital camera users to set white balance and achieve accurate exposure, either pre- or post-capture. The XpoBalance has two sides, each with three sections. On one side white, black and 18% reflectance grey; on the other three tones of grey, calculated to give normal exposure, one stop under, and one stop over. These can be used to give the preferred exposure balance before taking the shot, but the real benefit for the photographer working under pressure is to enable adjustment afterwards using the Levels control in a program like Photoshop. Just include a shot of the XpoBalance in each lighting situation and then use the black/white/grey side with the Photoshop dropper tool to adjust for shadows/highlights/midtones as required in Levels. Alternatively, the three grey tones allow exposure to be set one stop over or under. Save te settings, and then apply these to all the other photos taken in the same situation to achieve consistent results across all the shots.