Baader 2" Herschel Prism - Version V
Baader 2" Herschel prism for non-compromised solar observation. A new technology for light and heat absorption. Includes a 2" Solar Continuum filter. The Baader Herschel Wedge Prism is considered by many to be the finest on the market. This wedge uses a 2" Zeiss ultra smooth prism which maximizes contrast and sharpness. Baader incorporates many proprietary elements within their wedge, one of which is a specially enhanced optical design for stray light elimination.
Baader 2" Herschel Prism - V - Method of Operation:
- The sunlight enters the telescope unfiltered
- The design of the Herschel Prism deflects only 4.6% of the light by 90° to the eyepiece barrel
- The rest of the light is focused outside the Herschel prism; this cannot be used for observation because of the inherent high energy levels
- A special ceramic, developed for space technology, absorbs the extra light energy without heating its environment
- The prism housing can be kept closed and the risk of glare or fire is eliminated
- The Baader "Cool Ceramic Safety" Herschel Prism Ver. P offers the best solution for white light imaging of the Sun
- This product (BAD-HERSCH-V) is the Visual version, which is optimized for visual observing of the Sun; for solar astrophotography, order the "P" version.
Easy Positioning of the Sun:
A smart side effect of this Ceramic screen is the possibility of centering the sun in the telescope easily. Just place the Sun disk in the middle of the ceramic screen and you can start observing.
Both the Visual (V) and the Photo (P) versions contain the same Herschel prism. The difference lies in the different filter equipment. The Visual model includes the 2" Neutral Density ND 3.0 and 2" Solar Continuum Filter. The Photo version includes four 2" Neutral Density (ND 0.6, 0.9, 1.8, 3.0) and the 2" Solar Continuum Filter.
What kinds of telescopes can be used with the Herschel prism?
The Herschel Prism is intended for refractor telescopes without field flattener lenses on their rear side! The objective design (Doublet, Triplet, Air-Spaced, etc.) is not important. For all other kinds of telescopes we recommend a standard full-aperture type solar filter.
What About Your Finderscope?
Adding this solar filter to your telescope will adequately filter the light coming through your focuser, but have you considered what you’ll do about your finder scope?
Here are some suggestions for dealing with your finder that will assure you do not damage your eyes (or anyone else’s) by looking at the Sun through your telescope’s unfiltered finder:
- Remove Your Finder. Ditching your finderscope when solar viewing will remove the possibility of someone accidentally looking through it to spot the Sun. Of course, not having a finder makes centering the Sun in your eyepiece more difficult, but with practice, it can be done. Set the mount down so the telescope is pointing in the direction of the Sun. Put the main solar filter on so you can check your progress, and then move the telescope around until it casts a shadow that produces a nice, sharp silhouette of the scope. The OTA will look circular. Now move your telescope up or down with your hand controller, slow motion controls, or very carefully by hand if required while looking through the eyepiece. You will not get a warning when you are close, but you should be able to align with the Sun using this method. Practice ahead of time before any big event, like an eclipse, to make sure you’ve got the process down.
- Filter Your Optical Finder. This solution is not recommended for a reflex or red dot finder since it is too easy to accidentally look around the window. If you have one of these finders we recommend you either remove it or replace it with a dedicated solar finder (see below).
To make your optical finderscope safe for solar viewing you’ll need to buy a piece of Baader Solar Film for Visual Use. This film comes in different size sheets and cuts easily with scissors, allowing you to make your own filter. You can go super low-tech and use a rubber band to hold a piece of the film firmly around the finder or you can get fancy and build your own slip-on solar filter. However you attach the solar film, you need to make sure there are no light leaks at all and that it doesn’t accidentally fall off when you move your telescope around. Any unused film can store flat between two pieces of cardboard and will keep for years. It is nice to have around, just in case of a solar emergency :-)
- Buy a Dedicated Solar Finder. Check out the Tele Vue Sol-Searcher Solar Finder. This special finder can only be used when observing the Sun, but it works very well. The Sol-Searcher is reasonably priced and can be attached to your telescope with Velcro or with #10-32 screws (user supplied).