ZWO OAG-L-68 M68 Off-Axis Guider with 12 x 12 mm Prism

Description

The ZWO OAG-L-68 is a large-format off-axis guider designed for astrophotography configurations using large sensors and imaging trains requiring a wide optical aperture.

ZWO currently offers three versions of its off-axis guiders: OAG, OAG-L and OAG-L-68. The OAG-L-68 is therefore a specific model in the current ZWO range and should not be confused with the standard OAG-L.

The OAG-L-68 uses a large 12 x 12 mm prism. This large surface picks up part of the telescope's peripheral light beam and directs it toward the guide camera, providing a wider field in which to locate suitable guide stars compared with smaller prisms.

The effective light-passing aperture of the guiding system is 11.7 x 8.3 mm.

The off-axis guider has a mechanical thickness of 17.5 mm. Its aluminum alloy construction is designed to provide a rigid and stable mechanical connection within the imaging train.

This OAG-L-68 version is intended for configurations using an M68 connection. It is specifically designed for integration into large-format ZWO imaging systems and configurations requiring a large mechanical aperture.

The OAG-L-68 is particularly suited to the ZWO 7-position electronic filter wheel for 50 mm square filters and the ZWO ASI461MM Pro medium-format camera. ZWO presents this combination among its connection solutions for medium-format cooled cameras.

The system allows the main imaging camera and guide camera to be connected to the same telescope simultaneously. A separate guide scope is therefore not required. Since guiding uses light directly from the main telescope, the guide camera follows the same optical and mechanical system as the imaging camera.

The ZWO OAG-L-68 incorporates an integrated focusing system for the guide camera. ZWO distinguishes the OAG-L and OAG-L-68 from the standard OAG in this respect, as both larger models include their focusing mechanism for precise and stable guide-camera adjustment.

The large 12 x 12 mm prism is particularly useful when combined with a guide camera equipped with a relatively large sensor. It facilitates guide-star acquisition, especially with long focal length telescopes where the available guiding field becomes smaller.

For correct focusing, the guide camera sensor and main imaging sensor must be made parfocal relative to the prism. The optical distance from the prism to the main camera sensor must therefore correspond to the distance from the prism to the guide camera sensor. The integrated focusing mechanism provides precise adjustment.

During installation, the prism position must also be adjusted correctly so that sufficient light is intercepted for guiding without obstructing the imaging area of the main camera sensor.

With its large prism, integrated focusing mechanism, M68 connection and design for wide-aperture imaging trains, the ZWO OAG-L-68 is particularly suitable for demanding astrophotography configurations using large sensors and long focal lengths.

Technical specifications

• Manufacturer: ZWO
• Model: OAG-L-68
• Type: Large-format off-axis guider
• Application: Astrophotography autoguiding
• Connection: M68
• Prism dimensions: 12 x 12 mm
• Effective guiding light aperture: 11.7 x 8.3 mm
• Mechanical thickness: 17.5 mm
• Material: Aluminum alloy
• Guide camera focusing system: Integrated
• Guiding principle: Off-axis light pickup from the main telescope
• Separate guide scope required: No
• Main and guide cameras: Operate simultaneously
• Designed for wide-aperture imaging trains
• Suitable for long focal length configurations
• Suitable for large imaging sensors
• Specific compatibility: ZWO ASI461MM Pro
• Specific compatibility: ZWO 7-position EFW for 50 mm square filters
• Prism position: Adjustable
• Guide camera focus: Adjustable
• Parfocal adjustment: Prism-to-main-sensor and prism-to-guide-sensor distances must be matched