Astronomy Accessories Off Axis Guider Off-axis Star Guide for Telescope
The Deluxe Off-Axis Guider enables simultaneous astrophotography and guiding through a single refractor telescope.
Product Overview
The Deluxe Off-Axis Guider enables simultaneous astrophotography and guiding through a single refractor telescope. It directs a guide star image into the eyepiece using a small adjustable prism, eliminating the need for a separate guide scope. This reduces tracking errors from differential flexure and mirror shift, ensuring precise star alignment during long exposures.
- Prism size12.5mm x 12.5mm
- Adjustment typePrism tilt with captive thumbscrew
- Radial movementOver 100 degrees
- Focus adjustmentCoarse and helical fine
- CompatibilityMost imaging cameras including DSLRs
- Camera interfaceT-thread or 1.25" nosepiece
Key Benefits
- Eliminates need for a separate guide scope, reducing setup complexity and mechanical flexure
- Uses the same optical path for imaging and guiding, so both see identical tracking errors
- Prism tilt adjustment with captive thumbscrew allows fine alignment of guide star position
- Over 100 degrees of radial movement enables quick and accurate guide star acquisition
- Coarse and helical fine focus adjustments support precise focusing on guide stars
- Compatible with most imaging cameras, including DSLRs, when the telescope has sufficient inward focus travel
Application Scenarios
- Deep-sky astrophotography with a refractor telescope where precise tracking is critical
- Long-exposure imaging sessions requiring stable guiding without introducing flexure
- Setup of a single telescope system for both imaging and guiding, minimizing hardware
- Field use where compactness and reduced weight are important for portable setups
- Imaging with DSLR or other T-thread or 1.25-inch nosepiece cameras on a refractor
Who It Is For
- Amateur astrophotographers using refractor telescopes for deep-sky imaging
- Educational astronomy programs teaching long-exposure imaging techniques
- Amateur and hobbyist astronomers building compact, stable imaging systems
- Research labs or observatories using refractors for high-precision tracking
- Astronomy dealers supplying accessories to imaging-focused buyers
Problems It Solves
- Separate guide scopes introduce differential flexure, causing star trails during long exposures
- Mirror shift in refractors during guiding can misalign the image, requiring re-centering
- Guide star acquisition is difficult when the guide scope is offset from the main optical axis
- Multiple camera and scope setups increase weight, complexity, and alignment effort
- Lack of focus control on guide star images leads to blurred or unusable guide data
Technical Features
- 12.5mm x 12.5mm prism aperture for light path redirection
- Adjustable prism tilt with captive thumbscrew for precise guide star alignment
- Over 100 degrees of radial movement to position the guide star anywhere in the field
- Coarse and helical fine focus adjustments for accurate focusing on guide stars
- Designed for use with refractor telescopes with sufficient inward focus travel
- Supports auto guider cameras with T-threads or 1.25-inch nosepiece
- Single telescope system for imaging and guiding, eliminating external guide scope
Specifications
| Prism size | 12.5mm x 12.5mm |
|---|---|
| Adjustment type | Prism tilt with captive thumbscrew |
| Radial movement | Over 100 degrees |
| Focus adjustment | Coarse and helical fine |
| Compatibility | Most imaging cameras including DSLRs |
| Camera interface | T-thread or 1.25" nosepiece |
| Telescope type | Refractor telescopes with inward focus travel |
| Function | Simultaneous imaging and guiding through same telescope |
Specifications are taken from the AMADA product data for this item. Confirm critical dimensions with us in writing before ordering.
Customization Options
- Available in standard configuration as a complete off-axis guider unit
- No options for different prism sizes or mounting types listed in source
- No mention of custom finishes, coatings, or mechanical modifications
Comparison With Other Options
| Separate guide scope with T-thread or 1.25" adapter | The OAG eliminates differential flexure and mirror shift by using the same optical path for imaging and guiding; a separate scope introduces alignment errors and adds weight and complexity. |
|---|---|
| Basic off-axis guider without helical focus | This model includes helical fine focus adjustment, which allows more precise focusing on guide stars compared to coarse-only focus mechanisms. |
Use Guide
- Ensure the telescope has sufficient inward focus travel before installing the OAG
- Adjust the prism tilt using the captive thumbscrew to center the guide star in the field
- Use radial movement to position the guide star in a clear, unobstructed area of the image
- Use coarse focus first, then switch to helical fine focus for sharp guide star definition
- Connect the auto guider camera to the OAG using a T-thread or 1.25" nosepiece adapter
Guides and Applications
Frequently Asked Questions
What telescopes is this guider compatible with?
Designed for refractor telescopes with sufficient inward focus travel to accommodate the OAG and camera.
Does this require a separate guide camera?
Yes. The OAG works with auto guider cameras that have T-threads or a 1.25" nosepiece.
Can I use this with a DSLR camera?
Yes, provided the DSLR can be mounted on the OAG and the telescope has enough inward focus travel.
What is the purpose of the prism tilt adjustment?
It allows fine alignment of the guide star position in the eyepiece by adjusting the prism angle with the captive thumbscrew.
How much radial movement does the OAG provide?
Over 100 degrees, which allows positioning the guide star across a wide area of the field of view.
Request A Price On The Astronomy Accessories Off Axis Guider Off-axis Star Guide for Telescope
Send quantity, destination and the application. We will confirm the configuration, the price and the lead time.