The present invention relates to a method and an apparatus for determining the amount of light scattered in an object in a machine vision system comprising: a light source illuminating said object with incident light having a limited extension in at least one direction; and, an imaging sensor detecting light emanating from said object, wherein said emanated light is reflected light (R) on the surface of said object and light scattered (S) in said object, said detected light is resulting in at least one intensity distribution curve on said imaging sensor having a peak where said reflected light (R) is detected on said imaging sensor. A width (w) of said at least one intensity distribution curve around said peak is measured, whereby said measured width (w) indicates the amount of light scattered (S) in said object.