makro intermediate rings for M42 lenses (analog) can be freely combined compatible with manual and electronic lenses do not carry autofocus and aperture values trouble-free due to the lack of electronic components do not deteriorate the quality of photos due to the lack of optical elements cause a decrease in the brightness of the lens Product characteristics: Highest quality intermediate rings for macro photography. They are placed between the camera body and the lens. They increase the distance between the focusing plane of the lens and the photosensitive material in the camera (matrix or film) and thus achieve a larger scale of reproduction. Im further we move the lens from the camera, the better magnification of a given object we will be able to obtain. The offered set consists of three rings of different lengths: 7mm, 14mm and 28mm (they can be freely combined) including the smallest and largest have built-in threads: one fixing the rings to the body, the other allowing you to attach the lens to the rings. The whole set is made of high quality galvanized aluminum, durable, abrasion-resistant and not susceptible to glare. The rings do not have any glass or optical elements – this means that they do not adversely affect the quality of photos. Method for setting the aperture (applies to cameras with a depth of field preview button): Without the rings (with the lens on), we set the appropriate exposure parameters (including the aperture); press the depth of field preview button on the camera body (most SLR cameras have it) - this will close the aperture to the value set in the camera. Holding down the button, we remove the lens. Technical data: total length of the set: 49 mm length of individual rings without mounting thread: 7 mm, 14 mm, 28 mm execution: aluminium kolor: black fits all lenses with M42 bayonet