12-18-2018, 11:46 AM
Canon did consider the EF-M mount for FF, which would have been similar to Sony's FE. For lens design purposes, they decided to go with a wider mount, explained in a little detail here (Nikon made the same decision):
https://translate.google.com/translate?depth=1&rurl=translate.google.com&sl=ja&sp=nmt4&tl=en&u=https://dc.watch.impress.co.jp/docs/news/1158578.html
https://translate.google.com/translate?depth=1&rurl=translate.google.com&sl=ja&sp=nmt4&tl=en&u=https://dc.watch.impress.co.jp/docs/news/1158578.html