made of black aluminum - they do not cause reflections, reflections or glare
they do not degrade image quality (they do not have any optical elements)
are compatible with manual iris lenses
they can be combined freely
always work flawlessly (they don't have any electronic components)
allow the use of multiple lenses
allow the use of all body functions (only dedicated rings)
cause a decrease in the lens brightness calculated by the formula: Fr = F (f + d) / f [where: Fr - actual lens brightness; F- aperture set on the lens; f - focal length; lens (in mm); d - length of rings]