These variable apertures are excellent for light attenuation and as lens aperture stops. A lever on the top of the diaphragm controls the aperture. Do not use these in the unfiltered output of sources rated at more than 50 W; use either a liquid filter, dichroic mirror or neutral density filter first.

These variable apertures are excellent for light attenuation and as lens aperture stops. A lever on the top of the diaphragm controls the aperture. Do not use these in the unfiltered output of sources rated at more than 50 W; use either a liquid filter, dichroic mirror or neutral density filter first.