Abstract: An apparatus for producing spectrally different light distributions which have the same irradiance is disclosed. This apparatus contains a light source and an adjustable, opto-mechanical filter means. The filter means contains an adjustment means for simultaneously varying the spectral distribution of light passing through the filter while maintaining the flux of the light at a substantially constant irradiance level.

Abstract: In a video camera using a silicon diode tube or a similar acting light sensitive solid state pickup element as a light image sensing device, a light control device which detects light in the visual spectrum and upon receipt of visual spectrum light operates a mechanical switching device which positions a Cut I-R filter in front of the image sensing device for visual light illuminated objects and positions a optical or neutral density filter in front of the image sensing device in the absences of any visual light for detection of infra-red light illuminated objects. Different filters can be substituted for other illuminating light frequencies.

Abstract: Color wheel for lighting fixture, which includes a polygonal metal plate, which has slotted metal bars seated on the side edge of the polygonal plate with rectangular glass plates, e.g. dichroic filters adhesively held in the slots of the metal bars spaced. The glass plates are not in direct contact with the metal bars and are spaced close to each other, but not in contact, in a peripheral array.

Abstract: The invention is directed to a microscope equipped with neutral filters adapted to the objectives thereof. These neutral filters are introduced into the imaging beam path of the particular objective in an objective turret of the microscope in order to obtain an image brightness equalization when switching the objectives. The neutral filters are arranged on respective sliders and can be easily removed from the objective turret.