A quick-release device for clamping a quick-change plate of an optical device in a guide on a baseplate, the quick-change plate and the guide comprising complementarily formed guide surfaces, the guide comprising first and second mounting elements adjustable relative to each other, and a device for fixing the quick-change plate in place designed for adjusting the distance of the mounting elements to each other, characterized in that the device for fixing the quick-change plate in place comprises a lever engaging with a cam in a slotted link disposed in the first mounting element, such that a motion of the lever adjusts the first mounting element relative to the second mounting element.