Visual and photographic filters for contrast enhancement at all Newtonian and SC-mirror telescopes.
The effect of the element neodymium as filter material is very impressive. When added to optical glass it boosts contrast, increases the red colour in the image (especially for Mars & Jupiter)
Plane-optical polished; can be used [well before the focal point.] without any loss of sharpness as a single filter in front of a binocular or for afocal projection with digital cameras.