Product Description

Glasspath Correctors for Lens Telescopes, Newtonians and Schmidt-Cassegrains

A glasspath corrector 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 Baader Glaswegkorrektor (GK) Faktor 1.25 GC Factor 1.25 / Factor 1.70 / Factor 2.60

These three glasspath correctors 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" glasspath correctors 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 glasspath correctors. 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.

With these three lens systems, you can solve focus problems of almost all common telescope designs. The lens cell provides both a thread for the Zeiss dovetail of our Großfeld (Giant) Bino and the MaxBright® II as well as a T-2 clamping flange for MaxBright® und MaxBright® II! This flange can be clamped between the male and female threaded parts of every T-2 (M 42x0.75) threaded connection. This way, you can start to experience with many accessories which you couldn't use with your telescope before.

Glasspath Correctors 1:1.25 and 1:1.7

The lens units of these correctors are cemented and can be removed from their cell to mount them upside down. The convex (outwards curved) side must alwys face towards the telescope. The versions for T-2 and Zeiss dovetail only differ in the mounting direction and can be reconfigured, if necessary.

Zeiss Dovetail (Großfeld- (Giant) Binoviewer and MaxBright II, only for GC 1:1.25 and GC 1:1.7

The glasspath correctors 1.25x and 1.7x are screwed into the Zeiss Ringdovetail at the front of the binoviewer.

T-2 Coupling Nut (Maxbright®/Maxbright®II Binoviewer)

All glasspath corrector are installed with the lens configuration B (lens cell points away from the binoviewer). To do so, there is enough space or a matching thread as well in the T-2 star diagonals as in the 1 1/4" and 2" nosepieces. To save optical length, the lenses are not inserted into the binoviewer. This way, the beam splitter inside of the binoviewer can be very close to the front of the housing.

Telescopes with T-2 Thread

Whenever you can't reach focus with a new accessory for your telescope, because there isn't enough backfocus, you should check if our glasspath correctors may be the solution. Almost every telescope manufacturer offers a T-2 adapte for his telescopes. These adapters usually are very short, because they are designed to attach to a DASLR. At exactly this place, our glasspath correctors are inserted! We manufacture several eyepiece adapters, spacer rings and adapters with T-2-thread, so that it is almost always possible to create a working adaption.

Camera Lenses

Perhaps you still own a camera lens with T-2 thread. With many lenses by third-party manufacturers (e.g. Tokina, Soligor, Vivitar etc.) you can remove the bayonet ring and access a T-2 thread. By using a glasspath corrector and our Variable Locking/Sliding T-2-focuser or a 1 1/4"/T-2 eyepiece clamp, you can use your 1 1/4" prism diagonal and most 1 1/4" eyepieces together with your camera lens!