A device for measuring properties of fiber in a sliver (16) is constructed with a first (12) and second (14) curved aluminum guide piece that is coated with either TeflonTM or ceramic. The guides compress the sliver of fiber. A Xenon bulb (30) provides light which passes through a first transparent window (28) located in the first guide piece. The light then passes through the sliver of fiber and out of a second transparent window located in the second curved guide piece. The light is then focused by optics upon a charge coupled device camera (18). The charge coupled device camera uses an array of pixels to create an image of the compressed sliver of fiber. A pulse generator (38) provides simultaneous trigger signals to the Xenon bulb and the camera so that the image of the sliver of fiber is created at the same time as the light is produced. Processing means (36) identify patterns of dark pixels in the array as trash, neps, seed coat neps, and other impurities in the fiber by comparing the patterns of pixels in the array with patterns in a lookup table.