Farpoint 90mm D Style Dovetail Rings

Product Overview

Mount your guide scope on the dovetail — rigid, aligned, adjustable.

The Farpoint 90mm D Style Dovetail Rings are a pair of 90mm inner-diameter rings that bolt to a D-size (Losmandy-style) dovetail plate and carry a guide scope, finder, or other optical accessory on top of your telescope. Three adjustment screws per ring center the tube, grip it securely, and let you aim the guide scope precisely — a rigid platform for autoguiding and wide-field imaging.

Who Is This Product Best For?

This product is designed for telescope owners and astrophotographers who use Losmandy-style (D-size) dovetail hardware. It is an ideal choice if you need a precision-machined, reliable mounting solution that integrates with the Losmandy-style (D-size) ecosystem of plates, saddles, and accessories.

Why Choose This Product?

• Precision machined: CNC-machined and anodized for a tight, secure fit on Losmandy-style (D-size) hardware.
• Built to last: Aircraft-grade aluminum construction resists flexing under load and holds alignment.
• Trusted brand: Farpoint Astro is a respected name in telescope mounting hardware, made in the USA.

Recommended Uses

Use this telescope guide scope rings for visual observing and astrophotography setups that rely on the Losmandy-style (D-size) dovetail standard, including mounting optical tubes, guide scopes, cameras, and accessories.

Compatibility and Accessory Notes

Key compatibility and fit details:

• Includes: Two rings with 3-point adjustment screws (standard 1″ length)
• Ring inner diameter: 90mm
• Holds: Guide scopes, finders, and accessories with tube O.D. below 80mm
• Mounts to: D-size (Losmandy-style) dovetail plates — dovetail not included
• Adjustment: 3-point screws per ring — also available in short .5″ and long 1.5″ lengths
• Construction: CNC-machined in the USA

Important Limitations

This is a Losmandy-style (D-size) component and is not compatible with V-size (Vixen-style) hardware unless an adapter is used. Verify your telescope's mounting pattern and your mount's saddle width before purchasing.

Frequently Asked Questions

Will these fit my guide scope?
The rings hold any tube with an outer diameter below 80mm — the ring needs at least 10mm over your tube O.D. so the three adjustment screws per ring can center and grip it securely. If your tube is much smaller than the ring, long 1.5″ screws add reach. Using a V-size (Vixen) setup? See our Vixen scope rings .

Is the dovetail bar included?
No — the rings bolt to a D-size (Losmandy-style) dovetail plate you already have. Need the plate? See our universal D-size dovetail bars .

What is the 3-point adjustment for?
Each ring has three screws spaced around the tube. They center the guide scope in the ring, grip it securely, and let you fine-tune where the scope points — essential for putting a guide star on your sensor. Rings ship with standard 1″ screws; .5″ and 1.5″ sets are available separately.

Our Recommendation

If you run a Losmandy-style (D-size) setup, the Farpoint 90mm D Style Dovetail Rings is a dependable, precision choice that will integrate cleanly with the rest of your Farpoint dovetail system. Ontario Telescope and Accessories stocks the full Farpoint lineup to help you build a complete, matched mounting solution.