This single polarising filter consists of only one polarising layer. Unlike variable polarising filters, which are made up of two layers that can be rotated in relation to each other, the transmission of this filter cannot be adjusted. Such single polarising filters are ideal for use on Herschel wedges (also called Herschel prisms) for observing the Sun, since here the light is already polarised.
The filter is simply screwed into the filter thread of the eyepiece. The brightness of the Herschel wedge can then be adjusted by turning the eyepiece.
Ideal for Lunt Solar Systems 2" solar prism / Herschel wedge LS2HW