neuroanatomist said:
AvTvM, I know you have an M camera. Do you have an EF mount adapter? Do you use it? Do you like it?
yes. i do have the Canon EF-M/EF adapter and do use it, when i really want/need to mount a (large) EF or EF-S lens. Most often this is the EF-S 60 which handles and performs quite well - also with adapter. Prefer the longer focal length over the EF-M 28 Macro.
Next often I use the EF 50/1.8 STM ... whenever i want/need a faster + (relatively) longer focal length than what is available as native EF-M lens. Also handles very well with adapter. My cheap and simple "shallow DOF Portrait setup" ... in absence of an EF-M 85/2.4 IS STM lens.
Additional bonus with the Canon lens adapter i the included (detachable!) tripod foot that works with every Canon lens including those that dont come with lens ring/tripod foot or where Canon would want me to buy a lens-specific ring at insane prices and sometimes also hard to find.
Sometimes I also use EF 70-200/2.8 - eg. at concerts, when want 2 bodies along ... wide-angle eg 24-70/2.8 II on my 5D3. E.g. on me and EF-M + 70-200/2.8 L IS on tripod further back in room ... i dont shoot video, but it would presumably also work well for video.
And ocassionally I use my M as crop sensor tele extender .. .eg. tried out the Tamron 150-600 some time ago ... on both 5D 3 and on EOS M ... on static subjects [don't shoot sports or BIF or wildlife] ... eg trying to get "full moon over certain buildings or landscape features" ... where i always am focal length limited and want to use crop factor for max. tele effect / FOV ... 600mm x 1.6 -> 960mm ... handling of combo [on tripod] was good, AF performance with Tamron 150-600 was borderline ... whimpy LP-E12 battery had difficulty moving focal group i guess ...
I find the Canon EF/EF-M adapter well made, very compact, not grossly overpriced

... and handling easy. When i am "moon-chasing in the field" or some similar city-scape activity i typically have only 1 large (EF-mount) lens along ... and leave the adapter on the lens, when i switch to an EF-M lens in between.
Overall I do think I am pretty representative for what people might do in terms of adapting EF lenses to a small mirrorless body [no matter whether crop or FF].
I am very tired of always hearing "size advantage of small body is gone, as soon as one attaches large lenses to it".Of course it is. But hey, thats not, what i want. Or only on special occasions. What i want is a small, as universal and capable as possible set - camera body + a few small lenses. And the possibility to occasionally also use larger lenses - when needed and not available/possible "in small". I do not want to regularly a small mirrorles body with huge Zeiss Otuses or XXL big whites ... handheld. And nobody else in their right mind would.
All i want ... is a SMALL, LIGHT, CAPABLE, noise- and vibration-free MILC as my "universal" camera ... and for best possible IQ, DR, rez, low light capabilities and shallow DOF-potential I want a good FF sensor in it, rather than a "half-frame" APS-C one.
Due to many years of familiarity with Canon / EOS user interface and my firm belief it is overall "best in class", I would prefer if it came from Canon. So basically i am waiting for a "modern day, digital equivalent" to the [legendary, analog] Minolta CL system. At Minolta prices of course, not at Leica prices. And with the added possibilities to use all of the Canon EF lenses with a simple little "adapter" whenever I want to.
PS: yes, i am 100% sure i am not the only one waiting for such a setup.
