ZWO OAG-L Off-Axis Guider for Astrophotography

ZWO Off-Axis Guider L – Precision Guiding Without Compromises

If you’re serious about deep-sky astrophotography, precision guiding is essential. The ZWO Off-Axis Guider L (OAG-L) delivers a rock-solid guiding solution for larger format sensors, ensuring pinpoint accuracy for long-exposure imaging. Designed with high-quality anodized aluminum, this off-axis guider is lightweight, rigid, and built to integrate seamlessly with your ZWO camera setup.

Why Choose the ZWO OAG-L?

Unlike traditional guide scopes that are susceptible to flexure and differential movement, an off-axis guider (OAG) eliminates these issues by using the same optical path as your main imaging camera. This means sharper stars, better tracking, and fewer headaches when imaging faint galaxies, nebulae, and globular clusters.

The ZWO OAG-L stands out with its larger prism and optimized light path, making it the ideal choice for full-frame and APS-C sensors. The increased prism size (12x12mm) provides more guide stars within the field of view, ensuring reliable guiding even in star-poor regions of the sky.

Key Features

• Large 12mm x 12mm Prism – Bigger than standard OAG prisms, allowing more light to reach your guide camera for improved tracking accuracy.
• Ultra-Thin 17.5mm Profile – Maintains back focus compatibility with ZWO’s full-frame and APS-C cooled cameras.
• Lightweight and Rigid Construction – CNC-machined aluminum ensures no flex or unwanted movement, even with heavy imaging setups.
• Adjustable Prism Height – Allows fine-tuning of the guide camera position to maximize light capture.
• Wide Compatibility – Works with ZWO ASI guide cameras and most astronomy imaging setups using M48 and M54 threads.
• Easy Installation – Pre-threaded connections allow secure mounting with no additional adapters needed for ZWO cameras.

Optimized for Full-Frame Astrophotography

Most off-axis guiders are designed around smaller guide prisms, which can cause vignetting or limit guiding success when used with full-frame cameras. The ZWO OAG-L was specifically engineered to work with large sensor cameras, including the ASI6200MM Pro and ASI2600MC Pro, ensuring full illumination and a clear guiding image.

Ideal for Long-Exposure Imaging

Whether you’re capturing deep-sky objects through an apochromatic refractor, Newtonian, or Ritchey-Chrétien telescope, the OAG-L enhances your guiding accuracy without adding extra weight or flexure. The rigid build ensures your guide camera and main camera remain perfectly aligned throughout an imaging session.

Simple Setup and Calibration

The OAG-L is designed for quick integration into your imaging train. Simply attach it between your filter wheel and camera, align the prism with your guide camera’s sensor, and adjust the focus. Since the guiding and imaging cameras share the same optical path, once you’ve achieved focus on your main camera, minor adjustments to the guide camera will have you ready to track with precision.

What’s Included?

• ZWO Off-Axis Guider L
• 12mm x 12mm Prism Assembly
• M48 and M54 Threaded Adapters
• Guide Camera Holder with Locking Screws
• Hex Wrench for Adjustments

The Ultimate Guiding Solution for Serious Astrophotographers

If you’re looking for a reliable, lightweight, and high-precision guiding solution for full-frame and APS-C astrophotography, the ZWO Off-Axis Guider L is the tool you need. Whether you're imaging galaxies millions of light-years away or capturing the delicate structures of nebulae, this guider ensures your stars stay sharp and your exposures stay accurate—every time.

Operating Guide:

1. For guiding, OAG-L can only work with ASI Mini cameras like ASI174MM Mini, ASI290MM Mini and ASI120MM Mini.
2. Considering the large prism size, we don’t recommend you use OAG-L with telescopes whose clear aperture is smaller than M48.
3. Yet it is recommended to use with 2” EFW or 7x36mm EFW, and with APS-C cameras (ASI2600) or full-frame cameras (ASI6200/2400). The large clear aperture supports full-frame cameras without vignetting.
4. The major differences between OAG-L and M68 OAG are about the prism size and the threads. OAG-L removed the inner threads so you can directly use the screws to connect it to other equipment.
5. If the thread of your telescope side is M48, then you don’t need to remove the M48 sensor tilt plate coming with OAG-L. On the contrary, you need to remove it and use some other sensor tilt plate at the corresponding thread of your telescope.
6. While adding OAG-L into your optical train, please make sure the prism won’t block the camera sensor.
7. You can use the guiding screw to adjust the guiding camera’s focus length. Please make sure the distances from the prism to the main camera and to the guide camera are the same. To ensure the result, it is better to do this during the daytime for the adjustment will be very difficult at night.

Tech Details: