Baader Teleconverter Alan Gee II (10598)

The Alan Gee II Telecompressor is a versatile optical accessory designed for all Schmidt-Cassegrain (SC) telescopes. With a variable reduction factor ranging from f/3.5 to f/5.9, it offers significant advantages for CCD imaging systems by increasing the field of view and reducing exposure times. This telecompressor is ideal for users seeking to adapt their SC telescope for both visual and photographic applications, effectively offering "two telescopes in one" without compromising optical quality.

Unlike standard telecompressors, the Alan Gee II is designed to illuminate a 24x36 mm (35mm) format with minimal vignetting and reduced image errors such as astigmatism. It can also accommodate eyepiece-side accessories with long optical path lengths, such as star diagonals and bino-viewers, which are typically not supported by conventional telecompressors. The multi-coated achromat lens can be inserted into the baffle tube of the telescope for photographic use or mounted directly in front of bino-viewers for visual observation.

The mechanical design ensures secure placement of the optics while maximizing the use of the primary mirror's center hole and baffle tube. Despite its thin wall thickness, the individual barrels are securely connected via fine threads, allowing flexible configurations based on the accessories used.

Developed based on recommendations from Roland Christen (AstroPhysics), the Alan Gee II features an air-separated doublet with a flat image field and a focal length of 259 mm. For optimal correction, it should be positioned at approximately half the focal length in front of the eyepiece or camera's image plane. The ideal image distance from the camera-side lens surface to the focal point is 121 mm, with barrel combinations adjusted accordingly to suit different setups.

Specifications:
Coating of optical system: Multiple coatings
Usable for visual observation: Yes
Focal length reduction: Range 0.35-0.59
Appropriate for: SC telescopes

General Information:
Colour: Black
Type: Teleconverter
Type of build: Telecompressor