# What is the MTF curve?

The MTF (Modulation Transfer Function) curve shows the contrast value (between 0 and 1) of a sinusoidal image focused on a camera as a function of the frequency of the image. It gives information about the spatial response of the camera. This curve is usually obtained by the Fourier transform of the Line Spread Function, i.e. the signal response of the cameras to an extremely thin slot.