Explore FirstLight 127mm f/9.4 Doublet Refractor Telescope (OTA only)

A 127mm f/9.4 achromatic doublet refractor with a 2.5-inch hexagonal dual-speed focuser — the largest aperture in the FirstLight refractor lineup, sold as an optical tube assembly for observers who already own a mount.

The 127mm objective gathers 55% more light than the 102mm model, resolving finer detail on planets and pulling fainter deep-sky objects into view. The 1200mm focal length produces high magnifications with standard eyepieces — a 10mm eyepiece delivers 120x for splitting planetary detail, while the included 25mm Plossl provides a comfortable 48x for finding and framing targets.

The 2.5-inch hexagonal focuser with 10:1 dual-speed reduction is a significant upgrade over the rack-and-pinion focusers found on smaller FirstLight scopes. The fine-focus knob makes precise adjustments at high magnification smooth and repeatable — important for planetary observation and astrophotography. The 2-inch 90° diagonal accepts both 2-inch and 1.25-inch eyepieces via the included adapter.

Key Features

• 127mm (5") achromatic doublet objective, fully multi-coated
• 1200mm focal length, f/9.4
• 2.5" hexagonal focuser with 10:1 dual-speed fine focus
• 2" 90° diagonal with 1.25" adapter
• Includes 25mm Plossl eyepiece, red-dot finder
• Vixen-style dovetail for universal mount compatibility

Ideal For

• Observers upgrading from a smaller scope — 127mm resolves significantly more detail than 80–102mm refractors
• Planetary enthusiasts — the long focal ratio and dual-speed focuser extract fine detail at high magnification
• Mount owners wanting a big refractor — drops onto any Vixen-compatible equatorial or alt-az mount