CS-M42 adapter

Product Overview

The Player One Astronomy CS-M42 Adapter is a compact metal adapter that connects a CS-mount lens to an M42-threaded planetary camera. It carries CS female threads on one side and M42×0.75 male threads on the other, in a 6.5 mm-long body, so a CS lens can thread directly onto the camera's M42 front. Player One designed it for their planetary cameras, where you want to put a CS lens in front of the sensor.

Who It's For

This is a good match if you own a planetary camera with an M42 front thread and want to mount a CS-mount lens to it — for example a wide-field, all-sky, or CCTV-style CS lens for meteor, sky-monitoring, or wide-field capture. It is a mechanical thread adapter, so it fits any imaging train where a CS-to-M42 transition is what you need.

Key Features & Design

• CS female to M42×0.75 male: the CS side accepts a CS-mount lens; the M42×0.75 male side threads onto a standard M42 camera front.
• 6.5 mm length: the adapter adds 6.5 mm of mechanical length between the lens and the camera body.
• All-metal construction: machined metal for repeatable threading and durability.

Recommended Uses

• Mounting a CS-mount lens on an M42-threaded Player One planetary camera.
• Building an all-sky or wide-field camera around a CS lens.
• Any imaging setup that needs a CS-to-M42 thread transition.

Compatibility & Accessory Notes

One side is CS female, which fits CS-mount lenses; the other is M42×0.75 male, the standard thread on the front of Player One planetary cameras. The 6.5 mm length is a fixed mechanical value — it does not set a focus or backfocus distance, since a CS lens reaches focus through its own focusing helicoid. A C-mount lens has a longer flange and needs an additional C-to-CS ring before it will thread on here. If you are unsure whether your lens and camera pair through this adapter, send us your lens mount and camera model and we will confirm the fit.

Good to Know Before You Order

• Mechanical adapter only: it makes a thread connection and nothing else — no glass, no electronics, and no effect on the optical path beyond the 6.5 mm it adds.
• CS mount, not C mount directly: the lens side is CS. A C-mount lens threads on only with an added C-to-CS spacer.
• Player One does not publish a weight: the adapter is a small machined part; if the exact figure matters for your kit, send us a note and we will weigh one from stock.

Frequently Asked Questions

Is it difficult to set up?

No — it threads on by hand. The CS side accepts your lens and the M42×0.75 side screws onto the camera front, with no tools or adjustment.

What does it connect?

A CS-mount lens to an M42-threaded camera, such as a Player One planetary camera.

Can I use a C-mount lens with it?

Only with an added C-to-CS adapter ring. On its own the lens side is CS; a C-mount lens has a longer flange and needs that extra ring to reach focus.

Does it contain any glass or electronics?

No. It is a purely mechanical thread adapter — no optics and no electrical contacts.

Will it set my backfocus?

No. It adds a fixed 6.5 mm of length; a CS lens reaches focus through its own helicoid rather than a set spacing.

Bottom Line

In short: a 6.5 mm all-metal CS-female to M42×0.75-male adapter that lets a CS-mount lens thread onto an M42 planetary camera — a simple mechanical connection with no glass or electronics.