An objective assembly (100, 250, 300, 600, 800, 1000, 1200), comprising: an objective (104, 304, 604, 804, 1004, 1204) comprising a housing (112, 312, 1212) and a lens (116, 316, 616, 816, 1016, 1216) mounted at the housing, the lens comprising an outer lens surface; and a liquid handling device (108, 208, 308, 608, 808, 1008, 1208) mounted at the objective and configured to immerse the outer lens surface in a liquid, the liquid handling device comprising: a rim (325, 625, 825, 1025, 1225) surrounding the outer lens surface and defining a device opening through which the lens is exposed, the rim comprising a notch (629, 829, 1229, 1235); a conical portion (192, 292, 392, 692, 892, 1292) comprising a conical surface communicating with the notch; a delivery outlet (180, 380, 680, 880, 1080, 1280) communicating with the device opening; and a return inlet (606, 806, 1206) communicating with the conical surface, wherein: the liquid handling device defines a liquid delivery path from the delivery outlet to the device opening; and the liquid handling device defines a liquid return path from the device opening, through the notch, along the conical surface, and to the return inlet (606, 806, 1206), characterized in that the notch (629, 829, 1229) is formed on the conical portion (692, 892, 1292), and the notch (629, 829,1229) is adapted to catch liquid from the lens (616, 816, 1016, 1216), to draw the liquid into the notch (629, 829,1229), and to direct the liquid to flow along the outer surface of the conical portion (192, 292, 392, 692, 892, 1292) on the side of the lens (616, 816, 1016, 1216) at which the notch (629, 829,1229) is located, and into the return inlet (606, 806, 1206) that is located on the same side of the lens (616, 816, 1016, 1216) as the notch (629, 829,1229). an objective (104, 304, 604, 804, 1004, 1204) comprising a housing (112, 312, 1212) and a lens (116, 316, 616, 816, 1016, 1216) mounted at the housing, the lens comprising an outer lens surface; and a liquid handling device (108, 208, 308, 608, 808, 1008, 1208) mounted at the objective and configured to immerse the outer lens surface in a liquid, the liquid handling device comprising: a rim (325, 625, 825, 1025, 1225) surrounding the outer lens surface and defining a device opening through which the lens is exposed, the rim comprising a notch (629, 829, 1229, 1235); a conical portion (192, 292, 392, 692, 892, 1292) comprising a conical surface communicating with the notch; a delivery outlet (180, 380, 680, 880, 1080, 1280) communicating with the device opening; and a return inlet (606, 806, 1206) communicating with the conical surface, wherein: a rim (325, 625, 825, 1025, 1225) surrounding the outer lens surface and defining a device opening through which the lens is exposed, the rim comprising a notch (629, 829, 1229, 1235); a conical portion (192, 292, 392, 692, 892, 1292) comprising a conical surface communicating with the notch; a delivery outlet (180, 380, 680, 880, 1080, 1280) communicating with the device opening; and a return inlet (606, 806, 1206) communicating with the conical surface, wherein: the liquid handling device defines a liquid delivery path from the delivery outlet to the device opening; and the liquid handling device defines a liquid return path from the device opening, through the notch, along the conical surface, and to the return inlet (606, 806, 1206), characterized in that the notch (629, 829, 1229) is formed on the conical portion (692, 892, 1292), and the notch (629, 829,1229) is adapted to catch liquid from the lens (616, 816, 1016, 1216), to draw the liquid into the notch (629, 829,1229), and to direct the liquid to flow along the outer surface of the conical portion (192, 292, 392, 692, 892, 1292) on the side of the lens (616, 816, 1016, 1216) at which the notch (629, 829,1229) is located, and into the return inlet (606, 806, 1206) that is located on the same side of the lens (616, 816, 1016, 1216) as the notch (629, 829,1229).