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The diameters of EFM and RF mounts

Started 10 months ago | Polls thread
nnowak Veteran Member • Posts: 9,074
Re: The diameters of EFM and RF mounts
4

istscott wrote:

It's tough understanding what Canon was thinking with EF-M. The same could be said for Nikon with their CX mount, Pentax with Q, and Samsung NX.

Sony's choice is odd in a way too. Assuming the Wikipedia article is correct, E mount's diameter is 46.1mm whereas EF-M is 47mm. Does the narrow mount hinder their sensor based shake reduction on Full-Frame cameras? Maybe.

Yes, the smaller Sony mount limits IBIS travel.  Those wikipedia measurements are correct, but they don't tell the whole story.  Because of differences in the size of the mounting flange tabs and electrical contact block, the E mount can fit a larger rear element than the EF-M mount.

If these companies had forethought they would have simply been proactive and quickly created a mirrorless version of their mount by shrinking the flange distance and using the same diameter of their SLR era mounts once they saw Micro 4/3rds show up. Though, I do understand Nikon enlarging theirs due to F-mount being so narrow.

The Nikon F mount is measured different from how Canon and most others manufacturers measure their mount.  Nikon only measures to the tabs whereas most others measure the largest possible circle.  Measured like Canon does, the F mount is actually 47mm

I don't think any of the big camera companies did a great job anticipating market direction besides the Micro 4/3rds group for what it is. Even then I don't know if their forward looking mount helped them that much in the long run now that larger formats are becoming lower priced. Maybe other companies copies them too literally with a focus on small sensors and were worse off for it.

Totally agree.  Everyone seemed to be focusing on "smallest possible" instead of "most capable".

I'm fine with how the Canon's APS-C vs. Full-Frame mount separation has been, but what I use EF-M for works with the current lens selection plus contributions by Sigma and Viltrox. Do I want more options? Sure! But I don't need fast ranged lenses like some sports and wildlife APS-C photographers probably do.

I think if EF-M gets dropped it's going to be due to internal battles at Canon. Didn't EF-M start as part of the PowerShot division? I think Magic Lantern noted some type of firmware separation from the M50 onward. Maybe the RF group isn't thrilled with how well EF-M has done lately with minimal releases and fought to end it. Who knows! Maybe we will find out soon.

The original M and M2 clearly came from the DSLR division.  The firmware and hardware were ported right from the T4i and T5i respectively.  The M3 changed up the menus and behaved like a powershot.

While the specific M50 and M50 II models have been quite popular, the M system as a whole has not been extremely popular.  Canon still sells more DSLRs than M system cameras and Canon's long term plan is to migrate all of those DSLR users to the RF mount.  Canon may have decided against creating the M5 II to push more people towards the RP, but the bigger issue is the declining camera market.  Canon is now selling half as many interchangeable lens cameras as they did just a few years ago.  The number of camera models needs to go down and lines need to be consolidated.

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