With the new Baader 2″ Cool-Ceramic Safety Herschel prism Mark II (Visual and photographic versions), there is no better way for uncompromising Solar Observation / Solar Photography in white light as a Herschel wedge allows the use of highest magnifications on a refractor without loss of quality.
This new Baader 2″ Cool-Ceramic Saftey Herschel prism MK II model features:
- Integrated rotation mechanism for polarising filters – the best method for brightness adjustment in visual solar observation and solar photography in white light. This filter rotation mechanism allows filters to be rotated steplessly in the optical path. Since the Herschel prism emits single polarised light, a stepless brightness adjustment is made possible in combination with the optional Baader Single Polarizing Filter 2″ (#2408342) and the included Neutral Density Filter. All necessary filters always remain in the Herschel prism, even when changing eyepieces!
- Includes the Baader 7.5 nm Solar Continuum Filter 2″ (540nm) (#2961581) with 7.5 nm half-band-width for an uncompromisingly sharp solar image.
Herschel prisms must always be operated with additional light attenuation filters. Every Herschel wedge needs additional neutral density filters since the reflected energy of the first surface prism (4.6%) still is a factor of 1000 too large for the human eye. All Baader Solar Diagonals are delivered with a pre-mounted ND 3.0 Baader precision 2” light reduction filter and Solar Continuum Filter. The photographic version includes even more ND filters for selective light attenuation when using cameras and high magnifications.
- S58 dovetail – as on the Steeltrack focuser for the use of the following three adapters
- BDS 2″ Diamond Steeltrack® S58 to M48 BDS-Adapter (#2957204)
- BDS 2″ Diamond Steeltrack® S58 to M68i BDS-Adapter (#2957207)
- BDS 2″ Diamond Steeltrack® S58 to T-2 BDS-Adapter (#2957202)
e.g. for short adaptation of cameras
- A new 3-point adjustment system of the wedge, preset in the factory
- Safety Kerfs on the 2″ nose-piece
- Sturdy air-sealed IP 67 transport case made of ABS plastic
Available in two versions:
Baader Safety CoolCeramic Herschel Prism 2″ Visual (#2956510V) with Baader Neutral Density Filter 2″ (ND 3.0, T=0.1%) (#2458332)
Baader Safety CoolCeramic Herschel Prism 2″ Photographic (#2956510P) with Baader Neutral Density Filter, ND 3.0/1.8/0.9/0.6.
The advantages of the Safety Cool-Ceramic Herschel prism
Space-Technology: A multiple staggered light trap made of heat protection sheets and heat-absorbing special ceramics as the end of the light trap – similar to heat tiles on the space shuttle – absorbs the radiant heat without heating the surroundings too much. The prism also remains temperature-stable for a long time.
Enclosed housing: no risk of glare or fire from the emitted sunlight, observation is possible without danger
Solar Finder: The ceramic plate also acts as a screen for the sunlight beam. Aiming the telescope at the sun becomes very easy.
ClickLock Clamp: with a 15° rotation you clamp every eyepiece securely – even in winter with heavy gloves.
Short overall length: shortening the overall length by 30 mm for the use of DSLR or Binoviewers with optional T-2 adapter Diamond Steeltrack® S58 to T-2 BDS-Adapter (#2957202 , € 27) or Diamond Steeltrack® S58 to M48 BDS-Adapter (#2957204 , € 29)
Filter Holder: On the rotatable filter holder, all necessary filters are firmly installed in the housing – no danger when changing eyepieces!
Brightness adjustment for photography: To let enough light through for photography at high magnifications, the pre-installed ND3 filter can be replaced by weaker filters (sold separately, or included with the photo version). Baader Safety CoolCeramic Herschel Prism 2″ Photographic (#2956510P , € 645) .
The Herschel wedge is based on the principle of using only a small part (4.6%) of the incident light for the actual observation. These 4.6% are reduced again by a factor of 1000 to a harmless level by the ND 3.0 neutral density filter, which is installed as standard in both versions. The unequally larger, high-energy part of the light falls through the housing and forms a focal point in the air outside. Even far behind this focal point, this light concentration would still be irritatingly bright and dangerous if an inexperienced observer were to accidentally (or wantonly) look into the output beam. Therefore, our Herschel prisms have been using light traps for years to eliminate this risk. With the closed light trap with Cool-Ceramic protection plate, observing the sun with a Herschel prism is possible without danger for private persons as well as for public institutions and schools.
You do not need an additional objective solar filter in front of your refractor telescope to safely observe the sun with the Baader Cool-Ceramic Herschel prism and the built-in ND 3.0 filter!
Please note: Herschel prisms must not be used on Petzval systems or other telescopes that have glass in the optical path near the focal point. Multi-lens systems do not pose a problem as long as the optics are at the front of the telescope. As long as the light has not been focused (i.e., the energy has not yet concentrated at the focal point), the heat input is no greater than solar energy on a white surface in summer. Ergo, it is a long held and just as often disproved misconception that refractor optics degrade or get too hot. All refractor optics whether oil or air gap, which are distributed by the company Baader Planetarium, are absolutely able to make solar observations by means of Herschel prism. The oils used are all UV resistant. (However, we can only speak here for the products of the brands we know – if necessary, refer to the manual of your telescope to see if it is suitable for solar projection).
Especially interesting is solar observation with a large aperture telescope like a Triband-SCT – Schmidt-Cassegrain-based Multi-Purpose-Telescope, for Sun and Deep Sky (various versions available) – the Schmidt corrector equipped with an energy protection filter allows to use telescopes up to 11″ aperture also for solar observation with a Herschel prism!
Telescope side connection options (included as standard):
- 2″ (50.8 mm) nosepiece with safety groove and M48 filter thread
- Dovetail ring (ring groove) S58 x 3.7mm, e.g. for connection to Zeiss M68 and other Baader connection standards with optional adapters
Eyepiece side connection options (included as standard):
- 2″ (50.8 mm) Clicklock clamp with brass clamping ring
- Dovetail ring (ring groove) S58 x 3.7mm, as on SteelTrack focuser
Housing: Metal; milled and matte black anodized; pearl white textured finish
Example application use of the new Herschel Prism (additional accessories/products not included)