Player One 1.25″-to-M42 Rotolock Adapter

Product Overview

The Player One 1.25″-to-M42 Rotolock Adapter joins a 1.25″ fitting to an M42 × 0.75 (T2) thread using a rotolock quick-lock collar. A clockwise twist of the collar centers and clamps the 1.25″ side — clockwise to lock, counterclockwise to release — while the M42 × 0.75 thread takes a planetary camera or other T-thread accessory. It is designed for planetary imaging, where a centered, repeatable hold keeps the target on the sensor. The body is metal.

Who It's For

This is a good match if you run a planetary camera with an M42 (T2) thread and want to drop it into a 1.25″ focuser or nosepiece with a centered, secure hold each time, rather than relying on a single compression screw.

Key Features & Design

• Rotolock collar: a clockwise twist centers and clamps the 1.25″ side; counterclockwise releases it.
• M42 × 0.75 (T2) thread: takes a planetary camera or other standard T-thread accessory.
• Centered hold: the collar seats the accessory concentrically instead of pushing it off-axis.
• Metal construction: machined for a firm, repeatable clamp.

Recommended Uses

Planetary and lunar imaging with an M42/T2 camera dropped into a 1.25″ focuser, and general use joining a T-thread accessory to a 1.25″ fitting with a centered hold.

Compatibility and Accessory Notes

The adapter bridges a 1.25″ fitting and an M42 × 0.75 (T2) thread, holding the 1.25″ side with its rotolock collar. M42 × 0.75 is the common T-thread used by planetary cameras. It is a mechanical adapter only — no power or data passes through it.

Good to Know Before You Order

• Mechanical adapter only: it is purely a mechanical connection between 1.25″ and M42 × 0.75; it passes no electronic signal.
• M42 × 0.75 (T2), not M42 x 1: the thread is the 0.75 mm-pitch T-thread used on cameras, not the 1 mm-pitch M42 lens mount.

Frequently Asked Questions

Is it difficult to set up?

No — thread your M42/T2 camera onto the M42 side, then twist the rotolock collar clockwise to lock the 1.25″ side into your focuser. Twist back to release.

What is it best used for?

Planetary and lunar imaging with an M42/T2 camera, and joining a T-thread accessory to a 1.25″ fitting with a centered, repeatable hold.

What thread is the M42 side?

M42 × 0.75 — the standard T2 camera thread.

Bottom Line

In short: a metal adapter that pairs a rotolock 1.25″ collar with an M42 × 0.75 (T2) thread, giving planetary cameras a centered, repeatable hold in a 1.25″ focuser.