BinoLight path corrector (1.7x) for binoviewers (Baader)

• Glasspathcorrector Factor 2,6. Focus gain: ca. 55 mm
• Insert diameter: ∅ 38 mm
• Suitable to insert into the Baader MaxBright (Classic and MaxBright^® II) or Mark V Großfeld (Giant)-Binocular (#2456410 , ) € 1425,-
• A Baader Glaspathcorrector is not a Barlow lens! The reason for this name (in Germany the name Glaswegkorrektor^® is a protected trademark by Baader Planetarium) is only secondly the displacement of the focal point
• A Glaspathcorrector is primarily intended to correct the prismatic color fringing that occurs on Refractors due to the high amount of glasses used in binocular prisms
• Please note: The Baader MaxBright® II Binoviewer with case (#2456460 , ) € 479,- is the only Baader-Bino where you can choose between Zeiss ring-dovetail and T-2 thread adapter.

Glasspathcorrectors for lens telescopes, Newtonians and Schmidt-Cassegrains

A glasspathcorrector fulfills two purposes: On the one hand, it removes the colour aberrations which are caused by the prisms of the binoviewer at fast telescopes, and on the other hand does it move the focus point outwards so that you can reach focus even at telescopes with little backfocus. And you can use different glasspath correctors to achieve additional magnifications without buying a second pair of eyepieces.

Baader Glaswegkorrektor (GK) Faktor 1,25 GC Factor 1,25 / Factor 1,70 / Factor 2,60

These three glasspathcorrectors are inserted either into the binoviewer or the T-2-prism. Which one you need depends on the available backfocus. You can find information on how to determine the backfocus of your telescope in the manuals of our binoviewers. Please also note our special 2" glasspathcorrectors for Newtonians or Lens telescopes and SCs.

The reduction of the optical length was measured with the 2" focuser of a Traveler 105mm/f6 Apochromat with a pair of 35mm ED eyepieces, the Großfeld (Giant) Binoviewer with 90° T-2 prism diagonal and the glasspathcorrectors. The measurement was done with the GC placed between prism and binoviewer. If the GC is placed in front of the prism, the optical length is reduced approximately by another 15 mm.

"Supercharged" by design

The MaxBright^® II Binoviewer incorporates the knowledge aquired during thirty years of building astronomical binoviewers. It is superior to cheaper models in many details.

MaxBright^® II Binoviewer highlihgts

• The housing of the 27mm large prisms is made with our own die casting moulds, using Carl Zeiss production drawings. The non-slip synthetic leatherette finish provides extra grip when holding the binoviewer with heavy eyepieces in your hand.
• On the eyepiece side, the newly designed, self-centering Clicklock^® eyepiece clamps with diopter adjustment are immediately noticeable. Thanks to the ergonomic design, you can blindly distinguish between clamping and diopter compensation even in the dark. The inner parts are made of stainless steel for maximum stability. The high-quality eyepiece clamps are only the last part of the precisely collimated optical system, which is designed for highest magnifications. This is the only way to achieve the almost three-dimensional image and relaxed observation expected from a binoviewer.
• All optical surfaces of the Maxbright^® II feature a 7-layer multi-coating. The prism chairs (mounts) of the prisms are constructed like those of the Mark V Großfeld (Giant)-Binocular (#2456410 , ) € 1425,- . The clear aperture is 26 mm on the telescope side and 25,5mm on the eyepiece side – even our 35 mm eudiascopic eyepieces are illuminated without vignetting. In comparison to models with smaller prisms you can see a much larger part of the sky at the same magnification – similar to our Mark V Großfeld (Giant)-Binocular (#2456410 , ) € 1425,- .
• On the telescope side, either a T-2 cap nut or a dovetail ring with original Zeiss micro bayonet are available – both connection options are included in the scope of delivery and allow a very compact adaptation to all common threads as well as our T-2 prisms and mirrors. Compared to fixed nosepieces, this effectively saves a lot of backfocus. The MaxBright^® II is compatible with all Baader Glasspathcorrectors. According to optical calculations by Carl Zeiss, these correction lens systems shift the focus outwards so that you can still reach focus despite the approximately 11 cm back focus (the required inward travel of the focuser) of the binoviewer. They also compensate for the colour error that would otherwise be introduced through the prisms when using telescopes between f/4 and f/7. Glasspathcorrectors are not simple Barlow lenses, even if they resemble them. For this reason, in Germany the name Glaswegkorrektor^® is a protected trademark by Baader Planetarium.

Read the extensive 22-page test review by Bill Paolini (May 2nd, 2020)

In combination with a lens telescope or a Schmidt-Cassegrain we recommend the Baader T-2 Stardiagonal (Zeiss) Prism with BBHS ® coating (T-2 part #01B) (#2456095 , ) € 243,- or the Baader FlipMirror II Star Diagonal (#2458055 , ) € 228,- , to achieve a compact telescope adaptation. In addition, you can then choose a matching Glasspathcorrector

To select the right Glasspathcorrector, you need to know the backfocus of your telescope. You can read how to do this in the Manual of the Maxbright^® II Binoviewer.

For Newtonians,we recommend either the large 2" Glasspathcorrector® 1,7x for Newtons (#2456300 , ) € 217,- or the Glasspathcorrector 1:2,60 for Baader-Binoviewer (#2456317 , ) € 132,- .

For SCs or lens telescopes we recommend either the or the two T-2 Glasspathcorrectors Glasspathcorrector 1:1,25 for Baader-Binoviewer with T-2 thread (MaxBright® II and MaxBright®) (#2456314 , ) € 122,- and Glasspathcorrector 1:1,70 for Baader-Binoviewer with T-2 thread (MaxBright II® and MaxBright®) (#2456316 , ) € 127,- . The 1.25x Glasspathcorrector is used on lens telescopes mainly for removing the colour aberrations, which would otherwise be introduced by the long light path through the prisms of the binoviewer.

You don't necessarily need a Glasspathcorrector for Schmidt-Cassegrains with f/10. Especially for lower magnifications and thus larger fields vof view, the Alan Gee Telecompressor Mark II (T-2 part #20) (#2454400 , ) € 275,- is more interesting: It shortens the focal ratio to ca. f/5,9, which gives you a brighter image and a larger field of view. So, a C8 almost becomes a rich-field telescope – for comfortable observations with both eyes open!