Quote from: Haydn1971 on May 23, 2012, 03:52:42 PM
Speaking hypothetically, if a smaller sensor was used with a EF mount, couldn't the distance between the lens mount and sensor be reduced ?
No you can't. The flange to sensor distance is fixed as that is the 'projection plane' of the image for a given lens design. The specific design distance which an image is to be projected , relative to its flange mount plane.
Changing the distance between the mount and the sensor would render exsisting EF & EF-s lenses redundant, or at least unable to focus at infinity.
However, there may actually be more in this...
Canon have already adapted the EF mount so that EF-s lenses can be used, EF-s being lenses with shorter back focus, where the rear element protrudes deeper into the camera throat (thus the need to prevent EF-s lenses mounting on cameras with full frame mirrors)
So if the EF-s idea can work, then could an extension of this idea work? Retaining the EF / EF-s mount and flange distance, but with shorter back focus again lenses, ("EF-x?") so reducing the extension of the lens in front of the camera?
Obviously this would probably mean a mirrorless body but crucially retain an APS-C sensor. Remove the pop up flash, or move it off centre, and you now have a smaller body.
This would make the overall package of camera + lens smaller. Which is a more desirable objective. I mean, how daft do m43 cameras look with anything other than a pancake on them?
Such a solution would mean that although EOS-X users could use their EF and EF-s mount lenses, regular EOS FF and EOS APS-C users could not use the "EF-x" lenses....
UNLESS.. The EF-x lenses could initiate MLU when mounted, say a collapsable design where the rear element stays well forward until the lens is mounted and MLU engaged. So long as your EOS has live view then your EF-x lens would be fine.
I think I've cracked it.