baris3 you need at least 45mb write speed card, usually it comes with 90mb read speed but not always, i have one it was recommended to me a few posts before yours, works great and i can record at 2520x1418 as maximum size.
I had 10mb speed sdhc card class10 and i could record 11bit lossless raw in cinemascope 2.35:1 for 20 seconds which is quite good considering 10mb speed.It was 1768xsomething
You cant record above 1080p without using raw, if you want to record something else than canon 1080p files you have to use raw.
marcelo with some c lenses you get soft corners in 3x3 crop mode, there are some tests on youtubes with c mount raw which look great but jey probably use 5x5 crop
In worst case scenario you will sell the camera if you wont like it.
I own this original M back from 2014. I have 18-55 and 22mm f2 lens for it. I do not know if the dynamic video stabilization works while using magic lantern though. Because 18-55 lens have dynamic IS specifially for video mode (dynamic IS is a video thing not photography and only this lens have it).
My problem is, today I have tried recording something and I could not record more than 5 seconds. And what I am trying to record is mv1080. Not even 2.5k or something like that. It says "early stop, should have recorded more frames". Also, I can not set 2.5k, 4k because it says this crop mode does not support more than 1700x resolution, it says it only works in 5x zoom mode. And I do not know how to change the crop mode. I have tried to access every setting but I could not find how to set 3x3 crop mode. I have only found a thing like 3x zoom or something like that and I do not get what it does.
For the card, I have Sandisk Ultra 32gb. My fastest cards might be samsung microSDXC's mounted on SD adapter, I will give them a try. And I have tried both card overclock module on or off.
But all I want is record 10 bit or 12 bit mv1080 video. More bits mean more colors and quality right ? I have shoot projects on EOS M and canon 1080p is not that bad but I want more quality like a small cinema camera.
Also, the magic lantern stats (overlay) when shooting video have dissappeared. Now it is back to normal canon video shooting overlay. I tried resetting the config but it is still the same.
Can someone help me ? If I can not get it working in 1080p 10 bit, I am going to record without magic lantern.