Z mount lens adapter for QHY163M COLDMOS Astronomy Camera

The QHY163M COLDMOS Astronomy Camera is a $1100 USB3 camera with a 16MP cooled monochrome micro Four Thirds (MFT) CMOS sensor. It comes with an M42 thread about 18mm from the sensor plane, which is short for M42, but unfortunately too far for a Nikon Z-mount lens to hit infinity focus. In particular, the lens of astronomical interest is the new Nikkor Z 58mm f/0.95 S Noct, which seems to have relatively minor aberrations at the very bright f/0.95 maximum aperture. Although the lens is manual, it actually needs power for various things; however, it can be manually focused and used wide open without power.

The adapter design here replaces the M42 mount on the camera. Once the four central screws have been removed, the camera looks as shown in the photo. The printed adapter is then connected to the camera using the same four screws that held the M42 flange. Once the printed adapter is screwed in, the Z-mount lens is attached normally; there is a small slot in the adapter edge to aid alignment for inserting bayonet.

Print Settings

Printer Brand:

Anycubic

Printer:

Rafts:

No

Supports:

Resolution:

0.2 variable

Infill:

Filament: Any Brand PLA Black

Notes:

How I Designed This ===================

This part was designed using OpenSCAD. However, I did not have a Nikon Z mount reference when I began to design it, so I started with the rear lenscap design from https://www.thingiverse.com/thing:3861755 for the Z mount bayonet. The X and Y dimensions of that part had to be enlarged slightly to account for printer tolerance. Obviously, there's a lot more that's different in my design, but the core Z mount is still from that thing.

Note that the actual placement of the sensor in the QHY163M is oddly angled relative to the placement of the screws. It's about 4.5 degrees rotated. We corrected for this in the design here, but we don't know if this tilt is consistent across copies of the QHY163M. The rotation shouldn't matter very much, except the Nikkor is a very large and heavy lens, so you'll want to support the camera by the lens tripod mount -- which means any rotation would make the sensor tilted when the tripod mount is level.

Category: Camera