QHYOAG-M optical splitter

QHYOAG Off-Axis Guides from QHYCCD : Precision and Performance for Astrophotography

Optical dividers QHYOAG from QHYCCD, available in three main versions QHYOAG-S, QHYOAG-M, and QHYOAG-L, are essential devices for astrophotographers seeking optimum guiding precision. These tools enable the same optical path to be used for the main camera and the guiding camera, thus eliminating the problems of differential bending often encountered with external guiding systems.

Common features of QHYOAG

• Slim, robust mechanical design:
  • QHYOAGs are designed to be extremely thin, with the main body only 10 mm thick. The addition of a threaded adapter (M42, M54 or M62 depending on the model) slightly increases this thickness to around 13 mm.
  • The chassis is made of anodized aluminum, guaranteeing excellent durability while minimizing weight. This allows easy integration into complex optical configurations.
• Adjustable prism :
  • Each model incorporates a square prism to capture part of the light field for the guidance camera without interfering with the main image.
  • Prism size varies from model to model, influencing compatibility with different guidance cameras and sensors.
  • The prism is adjustable in position and can be locked to ensure perfect alignment with the optical system.
• Precise focus :
  • All models include a 1.25" helical focuser, compatible with QHY5II and QHY5III guidance cameras.
  • This mechanism enables precise focus adjustment, which can then be locked with thumbscrews to prevent accidental movement during use.
• Universal connection :
  • QHYOAGs attach directly to QHYCFW filter wheels or cameras via six screws, guaranteeing a solid, perfectly parallel mechanical connection.
  • They are compatible with a wide range of standard and optional accessories to suit various optical setups.

The three models: S, M, and L

1. QHYOAG-S:
   • Prism size: 8 x 8 mm.
   • Adapter thread: M42/0.75.
   • Compatible sensors: Suitable for compact sensors up to 1 inch (such as those used in compact CMOS/CCD cameras).
   • Recommended use: Ideal for lightweight or portable configurations with narrow-field telescopes or compact optical systems.
   • Advantages: Ultra-slim design for setups requiring low backfocus.
2. QHYOAG-M :
   • Prism size: 8 x 8 mm in the standard version; up to 10 x 14 mm in the Pro version.
   • Adapter thread: M54/0.75.
   • Compatible sensors: Suitable for APS-C or APS-H (intermediate size) sensors.
   • Recommended use: Perfect for intermediate configurations using filter wheels such as the QHYCFW3-M or cameras such as the QHY268M.
   • Advantages: Balance between finesse and ability to capture a larger field of guide stars.
3. QHYOAG-L :
   • Prism size: 8 x 8 mm in the standard version; up to 10 x 14 mm in the Pro version.
   • Adapter thread: M62/0.75.
   • Compatible sensors: Optimized for full-frame and larger sensors (such as those used in QHY600 or QHY461 scientific cameras).
   • Recommended use: Designed for professional configurations requiring wide spectral coverage and compatibility with large-aperture telescopes.
   • Benefits: Increased prism size in Pro versions to reduce vignetting on large sensors.

Main differences between S, M and L

• Prism size :
  • The S model features a smaller prism (8 x 8 mm), sufficient for smaller sensors.
  • The M and L models offer a larger prism size (up to 10 x 14 mm in their Pro versions), ideal for capturing more guide stars on larger sensors.
• Sensor compatibility :
  • Model S is limited to small sensors (1 inch or less).
  • The M model supports intermediate sensors such as APS-C/APS-H.
  • The L model is designed for full-format or larger sensors.
• Adapter thread :
  • S : M42/0.75.
  • M : M54/0.75.
  • L : M62/0.75.
• Specific applications :
  • S: Compact or lightweight configurations.
  • M: Intermediate configurations balancing performance and size.
  • L: Professional configurations requiring maximum precision over wide fields.

Practical applications

QHYOAG off-axis guides are particularly suitable for :

• Reduce differential bending by sharing the optical path between main camera and guide camera.
• Maximize the potential of guide cameras with large sensors by minimizing vignetting with an adapted prism (especially in Pro versions).
• Offer a compact yet robust solution for astrophotographers working with different types of telescopes, whether compact or professional systems.

Efficient summary

• Three main models for different sensor sizes (S, M, and L):
• S: For small sensors (8 x 8 mm prism).
• M/L: For intermediate or large-format sensors (prism up to 10 x 14 mm in Pro versions).
• Ultra-thin design (10 mm) with various thread adapters (M42, M54, M62).
• Compatible with QHYCFW3 filter wheels and other standard accessories via six sturdy screws.
• Built-in precision helical focuser for optimal focus adjustment.

QHYOAG off-axis guides are an essential solution for improving guiding accuracy while reducing the mechanical footprint of your astrophotographic setups!