Eyepiece Projection OPFA V with M44 thread

Eyepiece Projection OPFA V with M44 thread

Description

The OPFA V eyepiece projection adapter with M44 thread is a complete projection system designed for Zeiss telescopes featuring an internal M44 thread. It enables high-magnification planetary or lunar photography using digital or analog SLR cameras with removable lenses. This version is based on the standard OPFA design and includes a dedicated Zeiss-M44 adapter (#1508005) to ensure a precise and rigid connection to Zeiss instruments.

The system includes the OPFA sliding focuser, two 40 mm T-2 extension tubes, and the M44-threaded adapter. The assembly begins with the male M44 adapter, which threads directly into the Zeiss telescope’s female M44 focuser. This threaded interface ensures a centered, stable, and light-tight mechanical connection.

A 31.75 mm projection eyepiece (not included) is inserted into the focuser, which allows fine axial adjustment. This adjustment is essential to define the projection distance between the eyepiece and the camera sensor, determining the equivalent focal length (fE) via the formula:
fE = fprimary × ((a ÷ fEP) - 1),
where a is the projection distance and fEP is the eyepiece focal length. Greater distances or shorter eyepieces result in higher magnification.

The two included 40 mm T-2 extensions are used to establish this projection distance and can be extended further using components from the Baader Astro T-2 system. The assembly connects to the camera using a T-2 adapter ring specific to the camera body (not included).

The sliding focuser includes a locking ring that allows free camera rotation for optimal image framing. This feature is especially important for OPFA V, where the telescope connection is fully threaded and rigid, preventing physical rotation of the entire unit.

With a 38 mm internal diameter, the system accommodates standard eyepieces without significant vignetting. Its precise machining and rigid construction ensure perfect alignment and mechanical stability, even under long exposures or high-magnification setups.

This unit is supplied without a projection eyepiece or camera T-ring. It provides a professional-grade solution for classical eyepiece projection on Zeiss telescopes, offering modularity, stability, and full compatibility with Baader’s T-2 accessory range.

Technical specifications

• Compatible with Zeiss telescopes with internal M44 thread

• Telescope-side connection: M44 male thread (via adapter #1508005)

• Camera-side connection: T-2 male thread (M42 x 0.75)

• Internal connection: T-2 female thread (M42 x 0.75)

• OPFA sliding focuser for 31.75 mm eyepieces

• Fine axial adjustment of eyepiece position

• Locking ring for stepless camera rotation

• Includes two 40 mm T-2 extension tubes

• Eyepiece not included (requires 31.75 mm)

• Camera-specific T-2 ring not included

• Internal diameter: 38 mm

• Outer diameter: 60 mm

• Optical length: variable depending on configuration

• Net weight: 0.17 kg

• Light-tight, rigid, vibration-free construction

• Compatible with Baader Astro T-2 extensions

• Ideal for planetary and lunar imaging on Zeiss instruments