BAADER GLASSPATH CORRECTOR 1.25x FOR BINOVIEWER
Baader Planetarium
BAADER GLASSPATH CORRECTOR 1.25x FOR BINOVIEWER is backordered and will ship as soon as it is back in stock.
The Baader 1.25x Glasspath Corrector is designed for use with the MaxBright II and Mark V Binoviewers.
As the name suggests, it corrects the glass path through which light passes through the binoviewer's prisms, removing the chromatic aberrations introduced by the additional optical elements.
It also moves the focal point significantly, adding approximately 20mm of focus. When mounted in front of a star diagonal, an extra 15mm of focus is added. This is useful for telescopes which have limited backfocus.
Glass path correctors for lens telescopes, Newtonians and Schmidt-Cassegrains
A glass path corrector fulfils two purposes: On the one hand, it removes the coluor aberrations which are caused by the prisms of the binoviewer at fast telescopes, and on the other hand it moves the focus point outwards so that you can reach focus even at telescopes with little backfocus. And you can use different glass path correctors to achieve additional magnifications without buying a second pair of eyepieces.
Baader glass path corrector (GK) factor 1.25 GC factor 1.25 / factor 1.70 / factor 2.60
These three glass path 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" glass path correctors for Newtonians or Lens telescopes and SCs.
The reduction of the optical length was measured with the 2" focuser of a Traveller 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.
| Optical Length | without Corrector | with GC 1:1.25 | with GC 1:1.70 | with GC 1:2.60 |
|---|---|---|---|---|
| From the contact surface of the focuser – with 90° T-2 prism | 162 mm (can't reach focus) | 144 mm | 122 mm | 79 mm |
| straight, with 2" nosepiece (without prism, important for Newtonians) | 112 mm | 94 mm | 71 mm | 28 mm |
| straight, with T-2 quick changer | 123 mm | 105 mm | 82 mm | 39 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 ® and 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.
Glass path 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 always 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 (Giant) Binoviewer and MaxBright II, only for GC 1:1.25 and GC 1:1.7
The glass path correctors 1.25x and 1.7x are screwed into the Zeiss ring dovetail at the front of the binoviewer.
T-2 Coupling Nut (Maxbright ® /Maxbright ® II Binoviewer)
All glass path correctors 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 1¼" 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 glass path correctors may be the solution. Almost every telescope manufacturer offers a T-2 adapter for their telescopes. These adapters usually are very short, because they are designed to attach to a DASLR. At exactly this place, our glass path 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 adaptation.
Camera lenses
Perhaps you still own a camera lens with T-2 thread. With many lenses by third-party manufacturers (eg Tokina, Soligor, Vivitar etc.) you can remove the bayonet ring and access a T-2 thread. By using a glass path corrector and our Variable Locking/Sliding T-2-focuser or a 1¼"/T-2 eyepiece clamp, you can use your 1¼" prism diagonal and most 1¼" eyepieces together with your camera lens!
Specifications
| Optical design | Glass path corrector |
|---|---|
| Compatible telescopes |
Refractors, Schmidt-Cassegrains, Newtonians |
| Magnification | 1.25 x |
| Optical length |
≥ -30 mm |
| Connection eyepiece side |
M42 x 0.75 (T2), M34 |
| Weight | 20 g |
| SKU | BA2456314 |
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 Baader glass path correctors for binocular viewers
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