Just did the Sigma MC-11 mod for Canon EF-S lens mount

Started 2 months ago | Discussions
Stan in NH Senior Member • Posts: 1,371
Just did the Sigma MC-11 mod for Canon EF-S lens mount
3

Thanks to those forum members who have posted how to get the otherwise excellent Sigma MC-11 Canon EF to Sony E mount adapter to work with the EF- S mounts.

It was getting more than a little frustrating that the MC-11 would accept the EF but not the EF-S lenses from Canon.  It didn’t make much sense to me, since they are interchangeable on any camera that uses the Canon mount.

So,  based on the advice of others who have already done this ... and claimed it worked ... I got out my screwdrivers and went to work.  The screws that hold the outer chrome ring are in there really tight, and I was unable to move them with a small Phillips head screwdriver.  Luckily, I had a ratchet set with a small enough sized head, and was able to get them to move.  I was able to lift the outer ring and the spring behind it out in one piece, exposing the black plastic cover which restricts movement of the EF-S lenses.  Four more tiny screws, and that pried out easily, exposing the electronics.  It looks like it serves no purpose other than as a dust cover for the electronics.  I did not reinstall those four screws, but put them on some scotch tape and put them in a bag with the plastic cover.  I then just reattached the spring with the outer ring.

I then tried a Canon 24mm pancake lens, a Canon 60mm, and a Canon 55-250 kit lens.  My A6400 is set up with tracking AF.  Both lenses worked no differently than native glass.  Tracking was just as fast and consistent, exposures were right on.  I tried P, aperture priority, and shutter priority.  Everything worked as it should.  The lenses did seem to fit slightly looser than before, but not enough to actually move or cause any issues.  So, I now have access to all my Canon lenses, knowing they will be completely compatible with my A6400.

This is an easy modification to recommend.  It is simple to do, the hardest part being removing those really small screws.  And, as others have said, it works beautifully with no problems that I have yet seen reported.  Finally, if you don’t like it and feel you want to undo it, all you have to do is put back the plastic inside cover and it's right back to the original configuration.

 Stan in NH's gear list:Stan in NH's gear list
Nikon Coolpix P900 Sony Cyber-shot DSC-HX90V Canon EOS 80D Sony a6400
DigitalScott Regular Member • Posts: 168
Re: Just did the Sigma MC-11 mod for Canon EF-S lens mount

Thanks for that report.  I have heard of this before, but I don't have any EF-S lenses currently to try it.

Wondering...  Is part of that inner black plastic blocking insertion of the EF-S lenses? (I assume it must be)  Would there be a way to Dremel out a small part of the black inner plastic so that it can be re-inserted and still allow use of the EF-S range of lenses?

 DigitalScott's gear list:DigitalScott's gear list
Sony a6300 Sony E 55-210mm F4.5-6.3 OSS Sony E 16-50mm F3.5-5.6 PZ OSS Sigma 18-35mm F1.8 DC HSM Art Carl Zeiss Touit 2.8/12 +2 more
OP Stan in NH Senior Member • Posts: 1,371
Re: Just did the Sigma MC-11 mod for Canon EF-S lens mount

DigitalScott wrote:

Thanks for that report. I have heard of this before, but I don't have any EF-S lenses currently to try it.

Wondering... Is part of that inner black plastic blocking insertion of the EF-S lenses? (I assume it must be) Would there be a way to Dremel out a small part of the black inner plastic so that it can be re-inserted and still allow use of the EF-S range of lenses?

Since the EF-S lenses fit perfectly without that dust cover in place, it seems that the added thickness of the plastic is what prevents the lenses from seating all the way.  The shape of it conforms to the body and opening it fits on.  If you can find out which part of the cover actually restricts the movement of the EF-S lens, you should be able to grind that area down.

The plate really doesn’t appear to serve any function other than to cover the electronics inside, but those are not very exposed to any dust once the caps or a lens is on anyway.  It's probably a part you can't buy, so I opted to just keep it intact so I can sell the adapter as original if I want to at some point.

My question is why Sigma would design an internal plastic cover that makes EF-S lenses incompatible?  Without it, both EF and EF-S lenses work well, so not sure what the rationale behind this is.  IMHO, the MC-11 would be much more popular if they just redesigned that piece and kept more users happy.

 Stan in NH's gear list:Stan in NH's gear list
Nikon Coolpix P900 Sony Cyber-shot DSC-HX90V Canon EOS 80D Sony a6400
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