Player One M48F-M42M 17.5mm Extender

Product Overview

The Player One M48F-M42M 17.5mm Extender is a machined aluminium spacer that adds 17.5 mm of length while converting between thread standards. It carries M48 × 0.75 female threads on one end and M42 × 0.75 male threads on the other, so it both extends the train and steps M48 down to M42. It is used to reach a required backfocus while changing to the M42 (T-thread) interface.

Who It's For

This is a good match if your train needs both an M48-to-M42 step and about 17.5 mm of added length — for example, taking an M48 output down to an M42 camera or filter drawer at the right backfocus.

Key Features & Design

• 17.5 mm spacing: adds a precise 17.5 mm of length.
• M48 female to M42 male: steps M48 × 0.75 down to M42 × 0.75 in the same part.
• Aluminium 6061-T6: machined aluminium body, light and rigid.
• Mechanical only: no optical elements and no electronic connection.

Recommended Uses

• Backfocus spacing: add 17.5 mm toward a camera, filter, or corrector backfocus figure.
• M48-to-M42 step: convert an M48 interface to M42 while adding length.

Compatibility & Accessory Notes

One end is M48 × 0.75 female; the other is M42 × 0.75 male. It both extends the train and converts M48 to M42. Backfocus is a sum of every part in the train; if you are working out how much spacing you need, send us your camera, filter, and corrector setup and we will work it out with you.

Good to Know Before You Order

• Mechanical adapter only: it adds length and steps the thread — there are no optics and no electronic communication through it.
• Fixed length: the 17.5 mm step is not adjustable.
• Thread step: M48 × 0.75 female to M42 × 0.75 male.

Frequently Asked Questions

Is it difficult to set up?

No — it threads directly between an M48 female part and an M42 male part with no tools or adjustment.

How much length does it add?

17.5 mm.

Does it change the thread size?

Yes. It steps M48 × 0.75 female down to M42 × 0.75 male.

Bottom Line

In short: a machined aluminium 17.5 mm extender that steps M48 down to M42, for setting backfocus while changing to the M42 interface.