Farpoint 21.5 Inch 57.3 Series Universal Dovetail Plate (Radian Bar)

Product Overview

The Radian bar design, stretched to 21.5″ — the longest universal bar in the lineup, for long tubes and maximum balance range.

This 21.5″ 57.3 Series universal dovetail bar is Farpoint's extension of the Radian lightweight universal D-style dovetail bar we originally manufactured for OPT — the same light-weighted design with a variety of mounting hole options, scaled up for long optical tubes and heavy imaging trains. D-size (Losmandy-style). Machined of sturdy aluminum with a black anodized finish. CNC-machined in the USA.

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 dovetail plate 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:

• Bar length: 21.5″
• Series: 57.3 Series — extended from the original Radian bar design
• Bar standard: D-size (Losmandy-style)
• Design: Light-weighted universal bar — variety of mounting hole options
• Finish: Black anodized aluminum
• 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

Is this the Radian dovetail bar?
It's our extension of it. Farpoint manufactured the original 14″ bars for OPT (Oceanside Photo & Telescope), who sold them under the Radian Telescopes brand. With OPT now closed, we sell the line direct under the 57.3 Series name — and this 21.5″ stretches that same design for bigger rigs. The original length lives on as the 57.3 Series 14″ bar .

Why choose the 21.5″ length?
Long tubes and heavy imaging trains need wide ring spacing and room to slide the assembly for balance. At 21.5″, this is the longest universal bar in the lineup — if you don't need the reach, the 14″ original Radian length saves money and weight.

What mounts will this work with?
Any mount with a D-size (Losmandy-style) saddle. Mount still has a small Vixen saddle? Our D-size saddles and conversions upgrade it.

Our Recommendation

If you run a Losmandy-style (D-size) setup, the Farpoint 21.5 Inch 57.3 Series Universal Dovetail Plate (Radian Bar) 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.