Starlight Instruments Feather Touch Rotatable 1.25" Crayford Focuser

The 1.25" Crayford Drive

The 1.25" Feather Touch is a Crayford focuser: the drawtube is driven by friction from the focus shaft rather than by gear teeth. Feather Touch focusers have an ultra-low backlash system and ultra-smooth coarse/fine focus knobs as standard features, and every version of this focuser includes a brake and a compression ring.

Low backlash matters for both visual observing and imaging: when the knob turns, the drawtube responds, which makes it easier to settle on focus without overshooting.

10:1 Dual-Speed vs. Single-Speed: Control for Visual and Imaging

The Feather Touch 1.25" focuser is available in two configurations to match your primary observing style. The Single Speed version has coarse focus knobs only; the Dual Speed version adds a 10:1 fine focus knob.

The Dual Speed models carry a stainless steel reduction assembly in the pinion. This provides a 10:1 fine-focus ratio, where ten turns of the anodized aluminum fine-focus knob produce the same travel as a single turn of the coarse knob. This allows for incredibly minute adjustments, essential for hitting critical focus in fast optical systems, splitting tight double stars, or capturing the sharpest possible planetary data.

Two Travel Options: 0.75" (19.05mm) and 1.5" (38.1mm)

Starlight Instruments offers this focuser in two drawtube travel lengths to suit different telescope designs and applications. The choice between them depends on the required focus range of your optical system and the accessories you plan to use.

• 0.75" (19.05 mm) Travel: Starlight offers the 0.75" travel versions with the A15-1503-1 adapter for the Lunt 40/50mm solar scope.
• 1.5" (38.1 mm) Travel: The longer travel covers a wider range of focus positions. Starlight offers the 1.5" travel versions with the A15-1503-2 adapter for 6/8" RC scopes and the A15-1503-3 adapter for Meade 8" and Celestron 8" telescopes.

360° Rotation and Modular Adapters for Perfect Framing

The "Rotatable" designation signifies that the entire focuser body can be turned a full 360 degrees relative to the telescope adapter. This allows you to orient your eyepiece to the most comfortable position or perfectly frame your astrophotography target without ever loosening the camera or eyepiece in the drawtube. The focuser is held in its adapter by three setscrews (FTF1575 manual).

This focuser connects to your telescope via a separate, telescope-specific adapter (like the A15-1503 series), which is sold separately. Starlight's adapters for this focuser cover the Lunt 40/50mm solar scope, 6/8" RC scopes and Meade 8"/Celestron 8" telescopes.

The 1.25" Drawtube: T-Threads, Baffling, and Brake Control

The drawtube is engineered with features that support both visual and imaging excellence. For visual observers, a compression ring holds 1.25" eyepiece barrels. For imagers, the drawtube is threaded with a T-thread, so cameras and accessories can be threaded on directly.

Internally, the drawtube is machined with glare-resistant black baffling to absorb stray light and maximize image contrast. Every version includes a brake. On Feather Touch focusers the brake is a thumbscrew that adds tension to the pinion, which helps when the drawtube points steeply upward; turned all the way in, it locks the drawtube.

Motor Drive Upgrade: the Handy Stepper Motor

Starlight's Focuser Boss II brochure lists the HSM20 Handy Stepper Motor (sold separately) for any Feather Touch Crayford focuser. The HSM installation sheet mounts the motor on the pinion assembly after removing the gold fine focus knob and the black knob, so it applies to the Dual Speed versions.

The HSM clamps onto the pinion assembly, and turning its housing disengages the gears for manual focusing. It is driven by a Starlight controller (sold separately): the Focuser Boss II hub offers ASCOM control over serial, USB or wired Ethernet, with optional WiFi.

USA-Made Stainless Steel and Aluminum Construction

Starlight Instruments designs, machines, anodizes and assembles the components in-house in Columbia City, Indiana, which the brochure credits for its quality control. The focuser is built from hardened stainless steel, steel and anodized aluminum.

Other standard features from the brochure include the ultra-low backlash system, glare-resistant black internal baffling and tipped stainless steel set screws that are gentle on eyepieces.

Installation and Upgrades: The 4-Step Pinion Assembly Process

If you purchase a Single-Speed focuser, you can upgrade it to Dual-Speed at any time with the FTF1575 Dual Speed Pinion Assembly. The pinion assembly comes with the hex keys its installation uses (1/16, 3/32 and .050).

The process involves removing the focuser from its adapter, unscrewing the two socket cap screws holding the single-speed pinion, cleaning any debris from the screw holes, and attaching the new dual-speed assembly. The pinion block is internally symmetrical, allowing you to mount it with the fine-focus knob on either the left or right side to suit your preference. Finally, test by focusing slowly in and out with the coarse knob; if you feel a bind, loosen the set screw nearest the reduction assembly, rotate the reduction assembly 1/8 of a revolution and retighten it gently, as the manual describes.