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EF-S 24mm f/2.8 STM Compatibility with EOS M50 and EOS R6

Rising Star

I have been wanting to try a Prime lens and was thinking of grabbing the Canon EF-S 24mm f/2.8 STM Lens to use with my with M50 (I have the Canon adapter for EF/EFS to M) Two questions I have about it is will everything work with it and also I would like t know when I upgrade hopefully in the Spring to a R6 or better with the adapter that allows EF lenses to be used with RF will it allow EF-S lenses to work with the RF mount at well? Is there any problem anyway with auto-focus working with either of the configurations? I found an article here but it was so long and went into things so techniquly that it was far more confusing than helpful in answering the question especially since it also started naming off mounts from other name brands as well. My other options are the Canon EF 50mm f1.8 STM or the Canon EF 50mm f/1.4 USM Lens I would like something that will work well in lower light and shadows. I took some pictures of a band yesterday and they turned out to me horrible. I normally do not film people ofthen but it looks like something I will be doing more of at least in the Summers. I would love an 85mm L series but it is not in the cards at this time, body first then another L series. Oh how do you deal with people becoming camera shy? The band asked me to take pictures and then when I started to every time I pointed the camera in their direction they would move away.






EF and EF-S lenses will work on an R series camera. EF-S lenses, since they are designed for crop sensor cameras, will result in a cropped image on a full frame R series camera. 
In your bandstand photos your subject is the band, but they are a small part of the image and the camera is exposing for the bandstand. Compounding that is the fact that the bandstand is white. 
In order to properly expose the band you need to add some exposure compensation. Try adding +1 and experiment from there. 

John Hoffman
Conway, NH

1D X Mark III, Many lenses, Pixma PRO-100, Pixma TR8620a, LR Classic

Thank you. I also feel the bandstand is much to small to allow for decent photos. I did this on a whim, only brought the 15-45 lens, I could have brought better had I known in advance that I was going to do it but just found out about it 2 hrs. before hand and then the GF dropped on me that she wanted to go shopping so everything was rushed. I hate taking pictures when I am rushed. I know I am capable of better. There is another next month and I will bring a better lens or lenses as well as a tripod.

Greetings far out dude,

If you believe there is a full fame body in your future, I would not invest in a crop series lens.

Here's an example.  

The R6 has 20MP's

Put a crop series lens on it, your effective megapixels are now 12.5MP's.  The R6 is a great camera, but a crop series lens isn't going to do it justice.


An RF28mm would be a better option in this case.

Bay Area - CA

~R5 C ( ~RF Trinity, ~RF 100 Macro, ~RF 100~400, ~RF 100~500, +RF 1.4x TC, +Canon Control Ring, BG-R10

~DxO PhotoLab Elite ~DaVinci Resolve ~Windows11 Pro ~ImageClass MF644Cdw ~Pixel 8 ~CarePaks Are Worth It

Would either of the 50 mm that I mentioned be considered a full frame? I honestly thought that the other was a full frame as well being an EF lens even though it's an the EFS Thank you.


You don’t really want to use EF-S mount lenses on a full frame sensor camera body.  

The EF-S lenses will not even mount on a full frame, EF mount DSLR.  If you mount a Canon EF-S mount lens on an RF mount body with the Canon mount adapter, then image will cropped, as described above.

I discourage people from adapting EF/EF-S mount lenses to M-Series bodies like the M50 because of the significantly increased current draw over comparable EF-M mount lenses.  

If you really need or want a prime for your M50, then the only lens I’d recommend would be the EF-M 22mm f/2 STM.  The lens is razor sharp.  I have one and it almost never leaves my M3.  The M-Series cameras are great pocket cameras, but not so great cameras for general photography.  

Otherwise, I would look into a quality EF mount, manual only prime lens for your M50.  I’d recommend an utra wide angle lines, something like a Rokinon fully manual, full frame14mm lens.  Once you dial in the hyperfocal distance on the focus ring, then everything beyond a couple of feet will be in focus.  I have a cinema version of the 14mm lens, and it is fun to use on a mirrorless body because of the zero current drain on the battery.

The Rokinon lenses have had a bad reputation for flawed build quality.  I think they use the best lenses for the Cinema versions.  I have bought three, me and my two sons, and they have all be razor sharp and flawless.


"The right mouse button is your friend."

Rokinon 14mm T3.1


"The right mouse button is your friend."

I would want something that I could take to the new camera for sure which is why I am asking about EF lenses, otherwise I would like to get the EF-M 32mm lens from all the pictures I have looked at for  Canon Prime lenses. I shoot manual for my landscape shots and am getting better with that for wildlife so focusing would not bother me much.

By the way, I like the sepia, I am trying to learn to edit for it.

Rising Star

So is it just EF-S lenses that are cropped on a R6 or would the EF lenses be cropped as well, that is something I still do not understand. Thank you.