The Baader Mark V Giant Binoviewer is the fifth edition of the Carl Zeiss Jena giant binoviewer, developed specifically for astronomy and featuring 30mm prisms. The Mark V is the most elaborate binoviewer that Baader has ever produced.

The Mark V Giant Binoviewer is made entirely in Germany according to the high quality standards of and by the original suppliers of Carl Zeiss. All air-to-glass optical surfaces of the Mark V feature a recalculated 7-layer multi-coating for the highest clarity and transmission. 

The optical polish of the prisms, all coatings and the optical adjustment and orthogonality of the 30mm prisms are so precise that the image doesn't deteriorate even at the highest magnifications. Each binoviewer is tested and collimated at a magnification of 1000x on an optical bench from Carl Zeiss.

On the eyepiece side are two newly-designed self-centering Clicklock eyepieces clamps with ergonomic diopter adjustment, made for hassle-free use in the dark. The Clicklock clamps are so precise that they preserve the collimation of the optical system, even at the highest magnifications.

The telescope side features the Zeiss micro bayonet including the TQC heavy duty quick-changer, allowing low-profile adaption to many common threads. Unlike fixed nose pieces, this saves a huge amount of backfocus.

The Mark V Giant Binoviewer is compatible with Baader's Glasspath Correctors, which shift the focus point outwards so that you can reach focus with many different telescopes. Glasspath correctors are designed to correct spherical aberration introduced by the long light path through the prisms of the binoviewer. Additionally, they correct for the prismatic colour fringing that is introduced by the extra optical elements present in the binoviewer with telescopes faster than f/7, so all telescopes faster than this require glasspath correctors.

Glasspath correctors are essential to "extract" the focus in telescopes that do not have a long back focus. Like a Barlow lens, the focus point moves outward. This means you can use a binoviewer with almost any type of telescope including Newtonians (with the appropriate glasspath corrector).

Glasspath correctors are not essential for Schmidt Cassegrain telescopes. However, a glasspath corrector is still recommended for Schmidt Cassegrain telescopes to correct for the spherical aberration. Even though the light beams do not converge at a wide angle as in faster telescopes, the addition of a glasspath corrector will increase image sharpness.

The Mark V Giant Binoviewer features the TQC heavy duty quick-changer. To connect the Binoviewer to a telescope you will need either the  or the .

When the binoviewer is used with a diagonal, it is recommended to remove the eyepiece holder and connect the diagonal directly to the binoviewer using a T2 thread, as found on all Baader 1.25" diagonals. For Baader 2" diagonals, remove the ClickLock and connect the . Connecting the diagonal directly to the binoviewer allows to save precious back focus.

In combination with a refractor or Schmidt-Cassegrain telescope, we recommend the or to achieve a compact telescope adaptation. In addition, you can then choose a matching Glasspath corrector. Prism diagonals have a shorter light-path compared to mirror diagonals. This allows you to “save” some of the necessary back focus required by the binoviewer.

Recommended glasspath correctors

To select the right Glasspath corrector, you need to know the backfocus of your telescope. You can read how to do this in the manual of the Mark V Giant Binoviewer (see Downloads tab).

• For Newtonians, we recommend the  or the dedicated BA2456300 2" Glasspath Corrector for Newtonians 1.7x.
• For short refractors we recommend the .
• For SCs or long refractors, we recommend the .

• You don't necessarily need a Glasspath Corrector for Schmidt-Cassegrains at f/10. If lower magnifications and larger fields of view are desired, the is recommended. It shortens the focal ratio to approx. f/5.9, giving a brighter image and a much larger field of view.

Downloads

Instruction manual

Items included

• Baader Mark V Giant Binoviewer
• Zeiss Micro Bayonet for use with T2 QuickChanger
• TQC Heavy Duty T2 Quick Changer
• Resin hardcase