Fluorescence stereo microscopes should include a viewing shield. When you are working at the microscope you don’t want to look down and have a bright light in your face. The primary role of the shield is eye protection. With fluorescence you are illuminating the subject with a bright excitation source and it can be at minimum annoying – and potentially damaging, depending on wavelength – to look at the bright spot for too long. That bright light can also be detrimental to your eyes’ dark adaptation, which helps in seeing weaker instances of fluorescence.
Most fluorescence stereo microscopes do include a shield, and this is typically a piece of material of fixed color that extends from the bottom of the objectives. It is usually deep orange to red so that it can block the longest excitation wavelengths (typically in the green) that the system provides. The NIGHTSEA Model SFA Stereo Microscope Fluorescence Adapter system is unique in that it does not used a fixed color shield. We provide a shield that is made from the same material as our barrier filter so that it does double duty:
The shield is a modular component that is automatically included with each SFA Light+Filter Set. When you change from one excitation light source to another you change both the barrier filter and the shield. The barrier filter attaches instantly with magnets, and the shield pivots into place and is secured with a quarter turn of a thumb screw.
(Click for larger image, use left and right arrows to navigate through gallery)