OPFA I Eyepiece Projection Unit with 1.25" Nosepiece

OPFA I Eyepiece Projection Unit with 1.25" Nosepiece

Description
The OPFA I Eyepiece Projection Adapter with 1¼" nosepiece is a complete mechanical assembly for classical eyepiece projection in astrophotography. It is designed for DSLR or analog SLR cameras where the lens can be removed. The system allows magnified imaging by projecting the image from an eyepiece directly onto the camera sensor.

Based on the OPFA-4 core, it includes a sliding focuser with locking ring, two 40 mm T-2 extension tubes, and standard T-2 male thread on the camera side and T-2 female thread on the telescope side. The OPFA I version adds a 1¼" nosepiece (item #2458155) that allows insertion into standard 1¼" focusers, with a built-in safety undercut.

Eyepieces up to 38 mm outer diameter can be inserted into the sliding focuser and clamped securely. Fine adjustment of the projection distance is done by sliding the eyepiece. The locking ring allows full rotation of the camera to set the desired orientation.

Two T-2 extension tubes adjust the projection distance (a), which together with the focal length of the eyepiece (fEP) defines the effective focal length (fE) according to the formula:
fE = f(primary) × ((a ÷ fEP) - 1)

This configuration ensures a rigid, light-tight, and adjustable setup. Additional T-2 extensions can be added for higher magnifications. A T-ring specific to the camera model (not included) completes the assembly.

This system is ideal for planetary imaging and high-magnification setups with any telescope that provides a 1¼" focuser. It is fully compatible with Baader’s Astro T-2 accessory system.

Technical specifications

• Product name: OPFA I – Eyepiece Projection Adapter with 1¼" nosepiece

• Camera compatibility: DSLR and SLR with removable lens

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

• Telescope connection: 1¼" barrel with safety undercut

• Sliding focuser: yes, with locking ring

• Included extensions: 2x T-2 extensions of 40 mm

• Max eyepiece diameter: 38 mm

• Clear aperture: 38 mm

• Outer diameter: 55 mm

• Optical path length: variable

• Net weight: 0.17 kg

• SKU: 2458141

• EAN: 4047825010155

• Manufacturer: Baader Planetarium