

Caruba's zoom range includes 11mm and 16mm zoom rings, which can be used together or separately to shorten the focusing distance. Both zoom rings transmit electrical information, i.e. aperture and focus information, between the lens and the body.
The zoom ring is placed between the camera body and the lens, which reduces the focusing distance of the lens. The more zoom rings there are between the body and the lens, i.e. the further the lens is from the body, the closer the camera can focus. With zoom rings, the lens cannot focus far, so the rings are useful for close-up/macro photography.
Zooming out reduces the lens's brightness, but sharpness is not lost because there are no glass elements in the zoom rings.
Zoom rings increase the magnification of a lens according to the following formula: zoom millimeters divided by the optical length of the lens.
For example, when an 85mm lens (which has a magnification ratio of 0.13X) is placed between the 11mm extension tubes and the camera body, the magnification ratio increases by 0.13X (the equation is 11mm / 50mm = 0.129). So if the original magnification ratio of the lens was 0.13X, it is now 0.13X + 0.13X = 0.26X.
Included in the package