So I have just bought a new Canon camera and figured my Sigma 24mm 2.8 Superwide lens would be compatible with it, as it is an EF mount. The lens itself was given to me second hand and I had just been using it on M4/3rd cameras, so never needed to take of the adapter. Im trying to now but it won't even budge at all, Am I just being an idiot and its all part of the lens? Also this 'adapter' also acts as aperture, as it has a turning wheel to help adjust. I have attached pictures to see if anyone can help/give any advice!?

P.s There is a small hole where possibly the adapter release button may have been?

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  • \$\begingroup\$ It looks very much like this adapter and it seems to be missing the release button indeed. The video unfortunately doesn't show the button in action, but I guess you need to actuate it for the adapter to come off. \$\endgroup\$ Commented May 13, 2020 at 12:36
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    \$\begingroup\$ Releasing the adapter may be as simple as a paper clip pressing on the linkage peeking out of the hole. \$\endgroup\$
    – BobT
    Commented May 13, 2020 at 13:48
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    \$\begingroup\$ Gosh I feel so stupid, face to hand moment! Yes paperclip worked wonders, thanks for your help! \$\endgroup\$ Commented May 13, 2020 at 14:14
  • \$\begingroup\$ @LilyO'Brien-Mead You might as well write an answer describing what you did to solve the problem. \$\endgroup\$
    – xiota
    Commented May 13, 2020 at 15:37

1 Answer 1


The release button on your adapter seems to be missing. You need to see if you can use something to press the spring-loaded switch that seems to be visible in the hole left by the missing button.


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