Astromechanics ASCOM APS-C M42 to Canon Lens Controller Mark II
Astromechanics ASCOM APS-C M42 to Canon Lens Controller Mark IIAstromechanics ASCOM APS-C M42 to Canon Lens Controller Mark IIAstromechanics ASCOM APS-C M42 to Canon Lens Controller Mark II

Astromechanics ASCOM APS-C M42 to Canon Lens Controller Mark II

  (1 Review)
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About this product

Model:  am_c_lens_adptr_17-9.5mm

New ASCOM Canon Lens Controller from AstroMechanics

We are proud to announce the UK exclusive of this innovative new product which enables you to natively control the aperture and focus of a Canon EF/EF-S Lens (Canon, Tamron, Sigma, Samyang etc..) via USB.

Much easier than manually focusing or trying to stop down the aperture with masks.

17mm Base Adapter + 9.5mm Spacer

This is the most popular version suitable for most ZWO & QHY cameras.

Use without the 9.5mm spacer for mono cameras (ASI1600MM-Pro for example) with a filter wheel. 17mm base adapter + 20mm filterwheel + 6.5mm ZWO cooled camera = 43.5mm.

Use with the spacer with a colour camera (ASI293MC-Pro for example). 17mm base adapter + 9.5mm spacer + 11mm T2 extension + 6.5mm ZWO cooled camera = 44mm.

The 9.5mm spacer also has a 1.25" filter thread.

24mm Base Adapter

A special taller version of the base adapter, supplied without an extension piece to suit QHY8L, QHY10 and QHY12 cameras with a back focal length of 20mm.

Compatible Lenses: Most classic Canon lenses should work correctly. Tamrom SP 150-600mm, Canon EF-S 10-18mm 1:4.5-5.6 IS STM, Canon EF-S 18-135 1:3.5-5.6 IS USM and Sigma 85mm f/1.4 DG HSM Art (for Canon EF Mount) lenses are not compatible at this time.

Image shows an example setup with a ZWO cooled camera, camera holder, AstroMechanics lens adapter and a Canon EF lens. Additional items not included ;-)


  • ASCOM Compatible Canon Lens Controller
  • USB Controlled and Powered (required 2x USB ports)
  • Full metal bayonet - no plastic parts!
  • Tight and secure lens connection
  • Updated design - all components neatly housed in the adapter
  • No extra wires - only one mini USB cable with dual connectors
  • Reliable FTDI USB to Serial Chipset - remembers it's COM port between disconnects, usually requires no additional device driver installation
  • Supported by ASCOM, INDI, TheSkyX and includes a Windows Desktop Utility and a Lens API to develop yourself


Both versions of the base adapter (17/24 mm) are presented

17mm base adapter for most ZWO/QHY cameras.

24mm base adapter for QHY8L/10/12 cameras.

Standard spacer (9.5 mm, required to achieve the correct back focal length w/o FW))
17 mm base adapter + 9.5 mm spacer = 26.5 mm

Downloads / Manuals

ASCOM Driver, Manual, Desktop Utility, API Protocol and more can be downloaded from:

Astromechanics Downloads


Customer reviews

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A fantastic bit of kit!!
21 March 2022  | 

I have been autofocusing a pair of Canon 200mm prime lenses using a stepper motor driven belt drive system controlled by FocusMax. This has worked reasonably well but always had a bad issue with backlash which meant that often I was caught out by not having enough focus movement beyond infinity for FocusMax to get to a good focus. Well the Astromechanics focuser fixed that instantly as it drives the lens focus motor directly and consequently there is only a tiny amount of backlash. It is a doddle to get a great set of V-curves, and actually focusing the lens takes only seconds - it is extremely fast. The Astromechanics lens controller worked straight out of the box and I have no idea how I managed before without it. One point to note. Use the included 9.5mm extender to put your camera at the correct back focus to the lens. There is enough focus movement beyond infinity in a Canon lens for FocusMax to be able to complete a full V-curve.


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