Herschel Wedge Safety Information


Herschel Wedge and Astro T-2 System Schematic

(click on image for larger version)

The above schematic shows layouts possible with the Baader Herschel Solar Wedge. Please note, removal of the ND=3 (1000:1) filter cell is not recommended. Also, the above diagram shows the prior version Herschel Wedge. The new Cool-Ceramic Safety Herschel Prism functions identically, but the physical appearance is slightly different.

* Please read the following important Safety Information *

Herschel Wedge - Safety and Usage

(for US customers)

A Herschel Wedge Solar Prism is a professional tool for the serious Amateur, and delivers the absolute finest true white light high-resolution and high-contrast views possible from your telescope. The first surface uncoated reflective design results in a pure white light view, with no selective filtration, permitting you to see solar detail in the natural color or to permit further selective filtration in any wavelength desired. The solar disk will be seen against a jet-black background with granulation, spot detail and fine contrasts that you never imagined.

As with any solar viewing system (including glass or solar film objective solar filters), the Herschel Wedge Solar Prism requires responsible handling. Herschel wedge prisms have been used for many years, and are quite safe if some care and precautions are always observed. Be sure to read and understand all precautions before placing the prism into use. If you have any questions or doubts, please contact the manufacturer - Baader Planetarium (www.baader-planetarium.de). Safety warnings are also listed on the Warning Plate found on the side of the prism. Please do not remove this plate.

There are two versions of the "Herschel Wedge" available. Herschel Wedge "V" is mainly for visual observing. It contains the 2" housing equipped with herschel 23°prism, 2" eyepiece clamp and 2" chrome sleeve. Built in is a ND = 3.0 neutral density filter and the new "Solar Continuum Filter 540nm".

Herschel Wedge "P" is equipped like Herschel Wedge "V" but has additionally three more neutral density filters (D=1,8 or 0.9 and 0.6) to be used in exchange of the ND=3.0 filter for reaching the shortest possible exposure time at every magnification and to reduce the seeing effects.


1. For visual use: NEVER remove the build-in 1:1000 (D=3) neutral density filter and the "Solar Continuum Filter". The filters come already pre-mounted from the factory at the front of the 2” eyepiece holder, and is permanently fixed into the holding cell. Important: Before each and every use, check to ensure that the filter is in place and securely mounted in the prism (not loose, cracked, or broken).

2. ONLY FOR EXPERIENCED USERS: for photographic use you can remove the build-in D=3 filter with it´s male 2" threaded coupler against a second 2" coupling ring (included) to hold one of the other neutral density filters (D=1,8 or 0.9 or 0.6) These are delivered only with Herschel Wedge "P" (but are available separately too) for reaching the shortest possible exposure time in combination with the "Solar Continuum Filter". BE CAREFUL! NEVER USE THE HERSCHEL WEDGE COMPLETELY WITHOUT FILTERS! This may perhaps destroy your (digital-) camera or hurt your eye!

3. The "Baader Light Trap" renders the output beam harmless to the touch or sight. Please ensure the light trap screen is in place before each use, and encourage onlookers not to poke at or insert any objects up into the output area. The energy from the prism still must first contact the screen, and a careless prodding finger can possibly be inserted into this narrow region where the beam still has enhanced intensity.

4. Never leave the telescope outside unattended during use (a requirement for any solar viewing with any solar filtration device).

5. Prior to using any long accessories (barlows, etc) please first check and ensure that they do not protrude so far as to contact the internal filters. This will prevent the possibility for damage to the filter.

General Use:

1. As supplied, the prism is ready for visual use. It has two built-in filters: 1. Our exlucise "Solar Continuum Filter 540nm" wich greatly enhances contrast and reduces thermal seeing effects and a ND=3.0 neutral density filter.

2. A polarizing filter may also be used on the eyepiece to provide variable adjustment of brightness (the Herschel prism is partially polarizing). By rotating the eyepiece, you can easily adjust the brightness of the solar image to your taste.

3. Only use the Herschel Solar Prism with refracting telescopes. Reflecting telescopes may be damaged by the concentrated energy at the secondary mirror.

4. When using auxiliary optics (barlows, telecompressors, etc), always place them into the beam behind the Herschel Wedge - not ahead of the Herschel. Any optic placed ahead of the Herschel would be exposed to unfiltered solar energy and most likely will be damaged by the potential heat buildup.