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Herschelprism with ceramic and 2 "Fast-Lock Okularadapter

APM Herschel Wedge Manual

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 prism (also called Herschelprima) 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 Herschel prism is equipped with the ceramic light trap, an 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" eyepieceholder 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 more safe , but also of better quality. The image has more contrast, imore 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 Fastlock eyepiece clamp

APM White Light Wedge Packages Include:

  • APM 2" White Light Solar Wedge
  • MC-coated Pre-Installed ND 3.0 Filter
  • MC-coated Pre-Installed Polfilter
  • Metal Carrying Case
  • Die Cut Foam with room for accessories


Telescope side connection:
Eypiece side connection:
Clear aperature:
varible Polarisationsfilter:
Integrated ND3 Filter: