APM 2″ Herschel Wedge
The APM 2″ Herschel Wedge is used for solar white light imaging and white light visual observing. The APM White Light Wedge comes with a built-in ND3 filter which allows perfectly safe imaging or visual observing of the Sun.
The function of the Herschel wedge (also called Herschel prism) is based on the principle that only a small part (approx. 5%) of the incident light is used for the actual observation. The part, which is incomparably larger and also energetic, is guided through the housing and forms a focal point outside the prism. Even far behind this focal point, the light concentration is still very intense, so that (with older prisms) caution had to be exercised, so that no inexperienced observer would accidentally look into the output light beam.
The APM 2″ Herschel Wedge is equipped with the ceramic light trap, a multicoated integrated multicoated ND3 filter and (removable) multicoated polarizing filter.
The sun can be safely observed with the APM Herschel Prism.The image brightness can be adjusted by twisting of the 2 “polarizing filter by rotating the 2” eyepiece holders from outside . Thus, the Herschel Prism can be used both visually and also photographically same good!
The clear optical aperture is 46mm!
The use of the Herschel prism (in comparison with film filters) for sun observation is not only safer , but also of better quality. The image has more contrast, more sharpness and allow higher magnification.
Important note: The application of the Herschel prism is only suitable for refractors and schiefspieglers .
The production version has a white body !
The special features of APM Herschel:
– screwed on but also removable top-pole filter in the 2″ plug-in sleeve
– Twisting of the 2″ polarizing filter by a lever from the outside
– APM Fast-lock eyepiece clamp