Editing Monochromator (section)

===Stray light===
The ideal transfer function of such a monochromator is a triangular shape. The peak of the triangle is at the nominal wavelength selected, so that the image of the selected wavelength completely fills the exit slit. The intensity of the nearby colors then decreases linearly on either side of this peak until some cutoff value is reached, where the intensity stops decreasing. This is called the ''[[stray light]]'' level. The cutoff level is typically about one thousandth of the peak value, or 0.1%.