The Baader Mark V Großfeld (Giant) Binocular Viewer is the fifth edition of the former Carl Zeiss binocular viewer with 30 mm prisms and it is the most elaborate which Zeiss have ever produced.
The Mark V is made in Germany according to the high quality standards of Carl Zeiss. The optical polishing of the prisms, all coatings and last, but not least, the optical adjustment and orthogonality of the 30 mm large prisms are so precise that the image doesn't deteriorate even at highest magnifications. Each binoviewer is tested and collimated at a magnification of 1000x on an optical bench at Carl Zeiss.
The Mark V features a 7-layer anti-reflective multi-coatings on all air-to-glass surfaces, a high performance beam-splitter with dielectric splitter layer and self-centering 1¼" ClickLock® eyepiece clamps (without locking screws!), similar to the tool holders of CNC milling machines used for mechanical engineering.
Eyepiece clamps feature diopter adjustment allow perfect fine-focusing for each eye which is is essential for using any binoviewer. The clamp's 1:10 power gear ratio, means that a gentle, small rotation of 20° of the ClickLock® ring is enough to securely clamp (or release) every 1¼" accessory. Such a small rotation results in a secure lock which is at least as tight as a single clamping screw that is tightened with much more force.
Baader offer several glasspath compensator/correctors for the binoviewer which are manufactured according to optical designs developed by Carl Zeiss. The glasspath compensators correct spherical aberration. However, they are also designed to remove the colour aberration which will occur because of the long light-path through the glass in the binoviewer, if it is used with fast telescopes (with focal ratios between f/4 and f/7) because of the convergent light beams in these instruments.
The use of a glasspath corrector will move the focus away from the telescope (similar to a Barlow lens) so that you can use the binoviewer in almost any telescope. If you use "slow" telescopes like Schmidt-Cassegrains (SC), you do not need a glasspath compensator, because the light beams do not converge at such a wide angle. Nevertheless, they can still be used to achieve different magnifications. The sharpness will increase even at SC- and HD-telescopes. These glasspath "colour-aberration compensators“ are an important addition to the binoviewer. The housing of the three glasspath models with a clamping collar is designed to be inserted between T-2-screw-connections. This way, these lenses can be used at all telescopes, in different places of the light path, and you can achieve several distances for projection.
If you are looking for the best binoviewer for your high-end telescope, then the Baader Großfeld (Giant) Binocular Viewer Mark V is just what you are looking for!
User manual for Mark V Binoviewer