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STM lenses and older EOS bodies

Started Aug 31, 2014 | Questions thread
totleytom Contributing Member • Posts: 564
Re: STM lenses and older EOS bodies

GreenPig wrote:

Thanks - I was just making sure that any new communications protocol would be ok. Typically these things are backward compatible.

I'm not sure there is a new protocol. That was always touted as one of the great advantages of the EOS system, right from the start in 1987: the camera would issue a high-level instruction, e.g. 'change focus to a nearer focus point' or 'close the aperture diaphragm', and it would be the lens which would convert that into specific instructions appropriate to the technology in the lens. We've had lenses with micro-motors (e.g. as in the 50mm f1.8), several variants of ultra-sonic motors, and now STM lenses, and (subject to the EF/EF-S/EF-M differences) they all just work on whatever body.

Canon got it right 27 years ago, and we're still seeing the benefits.

 totleytom's gear list:totleytom's gear list
Canon EOS 90D Canon EF 70-200mm F4L IS USM Canon EF 40mm f/2.8 STM Sigma 17-70mm F2.8-4 DC Macro OS HSM | C Canon EF-S 24mm F2.8 STM
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