Physical Camera

If Exposure is enabled, the camera will simulate the exposure process, i.e. the rendered image will vary in its brightness in correspondence with the ISO, F-Stop and Shutter Speed settings.
White balance is used to prevent light sources (e.g., sky, sun, candles, etc.) from colorizing white surfaces. Set the White Balance value to that of the light source’s color (Tungsten refers to the filament coil in a light bulb). If the presets do not quite match your needs, you can select the Custom option and define a custom temperature via the Custom Temperature (K) value. Color hues can be defined without having to change the color of the light itself.
Of course white balance can be used to colorize renderings. The neutral value is Daylight (6500K). Generally speaking, lower values result in hues of blue and higher values in hues of yellow (directly opposite to the depiction above; the white balance, after all, is a corrective value).