The Mark V Binocular Viewer is the culmination of years of research and development, originally by Carl Zeiss Jena and further advanced by Baader Planetarium. It combines all the best features to provide a superb viewing experience: optical quality, critical collimation, high transmission coatings and diopter adjustment to individually focus each eye.
If you own the previous Giant Binocular Viewer (BPBINOV) model and need information, please click here.
ClickLock Eyepiece Clamps - The ClickLock mechanism grips your eyepiece firmly using a 3-point contact that accurately centers each eyepiece. Insert the eyepiece and lock it in place with a gentle twist of the outer locking ring (just two tenths of a full turn). The clamp applies gentle, even pressure to lock the eyepiece in place and centered. Please refer to additional information from Baader Planetarium regarding the ClickLock feature.
Diopter Adjustment - You can now achieve perfect focus for each eye with the silky smooth micro-focusing collar, which allows 8mm of focus travel.
Dielectric Coating of Prisms - The dielectric coating increases throughput by 8.9% from previous models. The coatings were carefully matched to the index of the glass used for the prisms. They allow maximum transmission at 510nm - exactly where the dark accommodated eye has its maximum sensitivity. This is especially important for night vision.
Diagonal Mirror - The Baader T-2 1.25" Maxbright Mirror Diagonal features a Sitall mirror with 140 coating layers. The solid metal case has T-2 connection threads on either side resulting in an extremely short light path. As part of the T-2 system, it allows a variety of configurations. We have offered both mirror and prism diagonals over the years. Both offer the same optical performance.
Interocular Separation Adjustment - Adjusting the eyepiece spacing does not affect focus. The interocular distance can be adjusted from 55mm to 75mm.
Removable 1.25x Compensating Optical Element - This optical element eliminates the slight color error and spherical aberration that a prism beam splitter naturally introduces into the light path of all binocular viewers. It allows you to enjoy wide-field, low-power views of deep-sky objects, as well as high powers. This element (also known as a Glasspath Compensator) was designed by Roland Christen of Astro-Physics and is essential for telescopes with fast focal ratios. Baader Planetarium was the first to introduce this feature for the binocular viewer. We also offer the 1.7x (BP4B) and the 2.6x (BP4C) Glasspath Compensators and the 2" 1.8x Glasspath Corrector for Refractors and SCTs (BPRSGC18) to provide higher magnifications. A 2" 1.7x Glasspath and Coma Corrector for Newtonians (BPNGCC17) is also available. [See this link for Glasspath Compensator Placement.] One of these optics should always be part of the optical path of telescopes with fast focal ratios unless a BARADV or BPFFC is used.
Quality custom case - Your investment is well protected in a high-quality custom foam-lined case. The case is included with Mark V Binoviwers shipping since September 2014.
Clear Aperture: 1.1" at the diagonal entrance w/o the compensator and 0.96" with the compensator.
Weight: 2.25 lbs with Mirror or Prism Diagonal and 2" Nosepiece
Mark V Binocular Viewer
1.25x Compensating Element (BP4A)
T-2 Mirror Diagonal (BP1A)
2" Secure-Grip Nosepiece (AP16T)
IMPORTANT: If you are using the thin 2" adapter (ADA2013) or the original 92mm f5 or f7 Stowaway, you should not use the AP16T nosepiece since the brass ring of these parts do not grab onto the AP16T securely. You can upgrade to the thin 2" adapter (ADA20132), or alternately, you can use the 2" nosepiece from Baader Planetarium (BP16), which must be purchased separately.
Magnification Alternatives with Your Mark V Binocular Viewer
The Mark V Binocular Viewer is well suited for lunar, planetary and double star viewing. When you wish to push the magnification higher in order to bring out more detail, we recommend that you thread the optical section of our Advanced Barlow (BARADV) into the front of the diagonal. This optional accessory lens narrows the incoming beam and results in the sharpest possible images at the eyepiece end of the binocular viewer. It may be used with or without the Glasspath Compensator, depending on the magnification desired. Another excellent option is to use the Fluorite Flatfield Converter Barlow (BPFFC) manufactured by Baader Planetarium to achieve even higher magnification. We suggest that you review the entire range of options in the FFC System (PDF document)
To achieve the definitive image it is better to do your magnification using a barlow in front of the Mark V than to increase magnification with short focal length eyepieces. A narrower light cone passing through the binocular viewer is what provides the sharpest images.
Examples of Approximate Magnifications:
1.25x using standard configuration with 2" Nosepiece and 1.25x Compensator
1.70x using standard configuration with 2" Nosepiece and 1.70x Compensator
2.40x BARADV threaded directly into the Mirror or Prism Diagonal - no Compensator
2.60x using standard configuration with 2" Nosepiece and 2.60x Compensator
3.00x BARADV threaded directly into the Mirror or Prism Diagonal and 1.25x Compensator
1.70x BPFFC threaded directly into the Mirror or Prism Diagonal – no Compensator
Mark V User Manual
Please clink on this link to open a PDF of the Mark V User Manual.
The assembly diagram linked below shows how the Mark V Binocular Viewer is used in various configurations. It also shows several adapters with brass locking rings that we offer for various scopes. These adapters can be used to securely hold the Mark V Binocular Viewer and other valuable accessories in place. Please see the assembly diagram for details.
Baader T-2 System
Use this binocular viewer with other components of the T-2 system for versatility.
Baader T-2 System Chart
Baader T-2 System Parts list. Astro-Physics carries some of these components designated by our part number that begins with BP and includes the reference number on the chart. We can special order any others that would like to have.