Baader Hyperion 68° 10mm Eyepiece - 1.25"/2"

An 8-Element Design with a 68° Field and 22mm of Eye Relief

The Hyperion 10mm uses 8 lens elements arranged in 5 groups, with a 68° apparent field and an 11.9mm field stop (Baader technical data). Baader sums up the series as offering ease of view even at high magnifications.

Eye relief is 22mm. The rubber eye cap can be stored folded down, especially for persons who wear glasses, or folded up.

Baader Phantom Group Coatings: Maximizing Contrast at 520nm

Every glass-to-air surface in the Hyperion 10mm receives Baader's Phantom Coating Group, a 7-layer broadband anti-reflection system. An anti-reflection layer system was worked out for each type of glass used in the Hyperion eyepieces, with very low residual reflection.

These coatings are optimized for peak effectiveness around 520nm, the green part of the spectrum where the dark-adapted human eye is most sensitive. A strong green reflex shows light between 500 and 550 nm being reflected and lost, while Phantom Group coatings appear almost colourless, showing an equally good effect across the visible spectrum, so that the least amount of light is lost for a night-adapted eye.

Dual 1.25"/2" Barrels and Variable Focal Lengths from 6.1mm

The Hyperion 10mm comes with both barrels. The 24mm long 1.25" barrel, which holds the first group of lenses, unscrews to reveal the included 2" barrel (Baader's drawing gives 50.9mm for the 2" barrel height), so the eyepiece fits 1.25" and 2" focusers and star diagonals.

• Filter Threads: The eyepiece incorporates both M28.5 (1.25") and M48 (2") filter threads, taking 1.25" filters on the 1.25" barrel and a 2" filter between the barrels.
• Variable Focal Length: By adding optional Baader 14mm or 28mm Fine Tuning Rings (FTRs) between the main eyepiece body and the front lens group (housed in the 1.25" barrel), you can modify the focal length. With a 14mm FTR it becomes 8.4mm, with a 28mm FTR it becomes 7.1mm; adding both a 14mm and 28mm FTR creates a 6.1mm focal length, increasing magnification without a Barlow lens.
• Safety groove: Both the 1.25" and the 2" barrel have a self-locking safety groove.

M43 and SP54 Threads for Afocal and Eyepiece Projection

All Hyperion eyepieces are suitable for afocal and classical eyepiece projection. The two system threads sit beneath the rubber eye cap and the large silicone thread-protecting ring.

• M43 Thread: This thread is designed for "classical eyepiece projection." With the Hyperion M43/T-2 ring (#2958080), the Baader Astro T-2 System adapters for Moon and planetary photography can be used, and any T-2 camera ring with an SLR or DSLR camera may be attached.
• SP54 Thread: This larger thread is intended for "afocal projection." It allows you to attach a digital camera, or video camera where the camera lens cannot be removed. Baader Hyperion DT-rings such as SP54/M28 (#2958028) and SP54/M37 (#2958037), used with the Hyperion 11mm extension ring (#2958090), adapt the SP54 thread to the filter thread at the front of the camera lens.

Parfocal Group, Binocular Use and Build

Baader's technical data lists the 10mm in the parfocal group of the Hyperion 68° series, together with the other focal lengths except the 24mm. Parfocal eyepieces need little refocusing when exchanged.

The winged rubber eyeshield of the Hyperion 68° eyepieces is ideal for binocular use. The body has an outer diameter of 58mm and the design data gives 391g for the eyepiece (our specification table gives a net weight of 0.42 kg). Only open the eyepiece at the M48 thread at the top of the 1.25" barrel; other joints are secured with Loctite, and disassembly elsewhere voids the warranty.