Lens Mounts

For components related to AXIOM Beta see - Parts:Enclosures and Associated Mechanical Parts.

1 Overview of Lensmounts

http://en.wikipedia.org/wiki/Lens_mount

This page contains information about the different lens mounts and the protocols used to communicate with the attached lenses.

1.1 E Mount

Seems to be a good choice because there are adapters available for almost every camera/lens type for reasonable cost. Even active mounts for Canon EF, etc.

http://en.wikipedia.org/wiki/Sony_E-mount

Specs:

• Outer diameter 46.1mm
• Flange focal distance is very short: 18mm
• Frame size APS-C, 35mm

Pros:

• Short flange focal distance allows mechanical adapters to cover pretty much any lens mount out there
• widely adopted

Cons:

• not an open standard
• licensing necessary for lens communication protocol -> reverse engineering required
• using stack adapters reduces the accuracy and ruggedness of the whole system

LexOptical E-Mount on Github - A work in progress reverse engineering of E-Mount communication protocol.

Sony opens E-mount specifications. Seems we are on the safe side with using an E-mount adapter...

1.1.1 E-Mount Bayonet Scans

Full 4800 DPI scans available for download at: http://files.apertus.org/AXIOM-Beta/e-mount-scans.zip

Screws are 1.6mm outer thread diameter so could be M1.6, screw total length is 5,75mm

1.1.2 E-Mount to EOS Adapter *Inside*

Inside of our E-mount to EOS adapter sample

µC Board to translate from Sony E to Canon EOS

EOS contacts with springs on the PCB side

JL ... position of the EOS mount contact springs

We can replace this board with our own adapter board to connect to the cameras I/O's

1.1.4 Active Canon EF Mount

1. body <-> lens communication protocol: http://www.magiclantern.fm/forum/index.php?topic=3796.0
2. pins and contacts: http://en.wikipedia.org/wiki/Canon_EF_lens_mount
3. EF-S protocol: http://pickandplace.wordpress.com/2011/10/05/canon-ef-s-protocol-and-electronic-follow-focus/

1.1.5 Nikon F-Mount

Picture of Nikon F bayonet mount components.

Measured Bayonet Thickness: 1.3mm

1. general information: http://en.wikipedia.org/wiki/Nikon_F-mount
2. body <-> lens communication protocol: https://nikonhacker.com/viewtopic.php?f=8&t=1437
3. technical drawing of F-mout http://en.wikipedia.org/wiki/Nikon_F-mount#mediaviewer/File:Nikon_F-mount_mechDwg.png

1.1.6 Micro Four Thirds Mount

1. body <-> lens communication protocol: http://preamp.org/revenge/four-thirds-communication-protocol

1.2 Open standard Mount

P+S Technik offers with their IMS mount an open standard. For AXIOM Beta the adapters are too expensive, but for sure an option for AXIOM Gamma.

Is there a affordable really open standard mount out there?

please add it here...

1.3 Talk with a Canon Lens

Research links for the Canon EF-S Protocol

Electronic follow focus experiment

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