Contactless fingerprint acquisition apparatus , the apparatus comprising: - a casing defining a cavity ; - a space for receiving a finger of a user; - a transparent wall forming a window between the cavity and the space for receiving the finger; - a translucent wall arranged opposite and remote from the transparent wall so as to provide the space between them; - a lighting source contained in the cavity and configured to emit illumination light illuminating the space ; - a camera configured to acquire an image of a fingerprint of the finger, when the finger is received in the space , without coming into contact with the apparatus ; the apparatus further comprising a polarization system configured to: - polarize the illumination light in a first direction before the illumination light reaches the space ; - polarize the illumination light in a second direction after the illumination light has passed through the space , with the second direction being different from the first direction; - polarize ambient light in the second direction emanating from outside the apparatus and propagating towards the camera , before the ambient light reaches the space ; and - polarize the ambient light in the first direction after the ambient light has passed through the space , wherein the polarization system comprises a first polarizer forming or being attached to the transparent wall and being configured to: - polarize the illumination light in the first direction before the illumination light reaches the space ; and - polarize the ambient light in the first direction after the ambient light has passed through the space , and before the ambient light reaches the camera; wherein the polarization system further comprises a second polarizer attached to the translucent wall and being configured to: - polarize the illumination light in the second direction after the illumination light has passed through the space ; and - polarize the ambient light in the second direction before the ambient light reaches the space . - a casing defining a cavity ; - a space for receiving a finger of a user; - a transparent wall forming a window between the cavity and the space for receiving the finger; - a translucent wall arranged opposite and remote from the transparent wall so as to provide the space between them; - a lighting source contained in the cavity and configured to emit illumination light illuminating the space ; - a camera configured to acquire an image of a fingerprint of the finger, when the finger is received in the space , without coming into contact with the apparatus ; - polarize the illumination light in a first direction before the illumination light reaches the space ; - polarize the illumination light in a second direction after the illumination light has passed through the space , with the second direction being different from the first direction; - polarize ambient light in the second direction emanating from outside the apparatus and propagating towards the camera , before the ambient light reaches the space ; and - polarize the ambient light in the first direction after the ambient light has passed through the space , wherein the polarization system comprises a first polarizer forming or being attached to the transparent wall and being configured to: - polarize the illumination light in the first direction before the illumination light reaches the space ; and - polarize the ambient light in the first direction after the ambient light has passed through the space , and before the ambient light reaches the camera; - polarize the illumination light in the second direction after the illumination light has passed through the space ; and - polarize the ambient light in the second direction before the ambient light reaches the space . <EOS>