A device in the spinning preparation, ginnery or the like for recognizing foreign parts or impurities in a fibre material stream or between fibre tufts, • including - a detector device (4 to 8), as well as - a source, adapted - to illuminate foreign parts in the fibre material or between fibre tufts with polarized light (G P , G s ), and - to cooperate with the detector device (5 to 8), • wherein the detector device (4 to 8) comprises a camera, - including • a beam splitter device made from prismatic wedges , ∘ adapted to split off a spectral range, and ∘ with a polarized beam splitter layer , adapted to divide a remaining spectral range into two or more polarization states, • first image sensors for at least one spectral range, adapted to detect the split off spectral range, and • second image sensors adapted to detect the two or more polarization states of the remaining spectral range, and - adapted to detect colour and polarization states, and • wherein air gaps are missing between prismatic wedges , which are disposed after splitting off the spectral range. • including - a detector device (4 to 8), as well as - a source, adapted - to illuminate foreign parts in the fibre material or between fibre tufts with polarized light (G P , G s ), and - to cooperate with the detector device (5 to 8), - a detector device (4 to 8), as well as - a source, adapted - to illuminate foreign parts in the fibre material or between fibre tufts with polarized light (G P , G s ), and - to cooperate with the detector device (5 to 8), • wherein the detector device (4 to 8) comprises a camera, - including • a beam splitter device made from prismatic wedges , ∘ adapted to split off a spectral range, and ∘ with a polarized beam splitter layer , adapted to divide a remaining spectral range into two or more polarization states, • first image sensors for at least one spectral range, adapted to detect the split off spectral range, and • second image sensors adapted to detect the two or more polarization states of the remaining spectral range, and - adapted to detect colour and polarization states, and - including • a beam splitter device made from prismatic wedges , ∘ adapted to split off a spectral range, and ∘ with a polarized beam splitter layer , adapted to divide a remaining spectral range into two or more polarization states, • first image sensors for at least one spectral range, adapted to detect the split off spectral range, and • second image sensors adapted to detect the two or more polarization states of the remaining spectral range, and • a beam splitter device made from prismatic wedges , ∘ adapted to split off a spectral range, and ∘ with a polarized beam splitter layer , adapted to divide a remaining spectral range into two or more polarization states, ∘ adapted to split off a spectral range, and ∘ with a polarized beam splitter layer , adapted to divide a remaining spectral range into two or more polarization states, • first image sensors for at least one spectral range, adapted to detect the split off spectral range, and • second image sensors adapted to detect the two or more polarization states of the remaining spectral range, and - adapted to detect colour and polarization states, and • wherein air gaps are missing between prismatic wedges , which are disposed after splitting off the spectral range. <EOS>