The diagonal prism not only allows for comfortable viewing, it also erects the inverted image of the telescope, making it suitable for nature observation. An erecting prism is also a worthwhile purchase for moon observation, as the orientation of the moon in the eyepiece corresponds to the natural orientation of the moon.
BBHS (Broad Band Hard Silver): Silver is the first choice as a mirror material, but it must be protected against corrosion. The popular dielectric mirrors are more robust, but usually only reflect in visible light between approximately 400 and 700 nm. For a viewing experience that is equivalent to viewing without a mirror, BaaderBBHS® mirrors use an additional BBHS® first surface silver coating that is elaborately sealed against corrosion, which is responsible for the excellent brilliance and richer colours compared to simpler prisms. The silver coating is stabilised for long-term durability by a hard protective layer. This corresponds to the weather resistance of anAlSiO2 coating on a Newtonian mirror.
Unlike purely dielectric coatings,BBHS® offers a much wider spectral window with 98-99% reflection from just over 390 to 2000 nanometres and also allows deviating viewing angles without any loss of reflectivity – the silver produces no stray light whatsoever. The trained eye simply recognises more colours, especially with short-focal-length APO refractors. Especially when observing planets at maximum magnification, a significant colour intensification is easily noticeable compared to all previous coatings. In addition, a significant increase in contrast is noticeable due to the absence of any stray light.
Only glass ceramics are used as the substrate material for theBBHS® coating to ensure extremely fast temperature adaptation and image stability in combination with the CNC-milled aluminium housings.
The Baader ClickLock system: you will never want to attach your 2" accessories in any other way again.
The effectiveness and stability of the mechanics of the ClickLock system have been proven over years of testing and use of the smaller 1.25" ClickLock clamp system. The 2" ClickLock system is even more solidly constructed mechanically.
- 20° rotation of the clamp lever is enough to safely and securely attach 2" accessories.
- the heaviest load so far tested is a complete C14 with screwed on SCL clamp (2956233) and a 2" Click Lock star diagonal (2926100) and Scopos 30mm extreme eyepiece (3004030). The C14 was hence lifted on the eyepiece. However, we must point out that it is not recommended copying this test setup.
- the built-in ratchet indicates the position of the clamp both acoustically and by feel. So even in the dark and without having to look, you always know whether the clamp is open or closed.
- massive clamping ring - holds the most expensive accessories absolutely securely without causing scratches or pressure marks.
- CL clamp - available for a wide range of telescope systems. The extensive range available enables Baader 2" ClickLock clamps to be retrofitted onto a wide range of telescopes.(ClickLock clamps for Vixen and other brands are in preparation)
- the position of the clamp lever is adjustable by 6 camera slotted screws, or 6 Allen screws allow the position of the CL clamp to be adjusted with Hex key, making it optimal or left or right-handed users.
Which is better: mirrors or prisms?
Nowadays, a good diagonal mirror is roughly equivalent to a prism, but both have their own characteristics. Diagonal prisms used to be common because the mirror coatings aged and lost their reflectivity – an uncoated prism was more stable in the long term.
As light passes through a prism, it is influenced (refracted) by the prism, especially at fast aperture ratios, and can in principle lead to colour aberration – for this reason, it was included in the optical design of some telescopes (e.g. ZEISS APQ) so that these telescopes with prisms deliver a more colour-pure image than those without. For fast telescopes that were designed without a prism, mirrors are the better choice; the limit is in the range of f/6 to f/7.
Transmission and durability are no longer a problem today: all Baader mirrors and rear-coated Baader prisms deliver excellent transmission for decades. A simple aluminium mirror (without "enhanced" coating), as found in many telescopes, often has only around 80% reflection after a few years and tends to produce reflections, whereas a good mirror (dielectric or BBHS silver-coated) can achieve 96-99% permanently.
Practical experience shows that refraction in a prism produces less stray light than reflection on mirrors, unless a great deal of effort has been made during the manufacture of the mirrors to bring them to the stray light and contrast level of a prism. This is why many planetary observers still prefer a prism today. However, don't forget that a prism, just like the rest of the telescope optics, must adapt to the ambient temperature!
Another advantage of Baader prisms is their significantly shorter optical length, which is why we recommend Baader T2 diagonal prisms with a short housing for observation with a binocular head. This often makes it possible to focus when other diagonal mirrors fail.
