09-07-2017 07:32 PM - edited 09-08-2017 06:37 PM
Rokinon lenses come with different lens mount options. First and foremost, check the lens [mount] on any third party lens.
09-08-2017 11:28 AM
Waddizzle makes a good point - make sure it is designed for Canon EOS mount.
Also, most Rokinon lenses are completely manual... and that includes a manual aperture ring.
I think Rokinon makes two different Canon mount versions of that lens... one offers auto-aperture.
Some astrophotographers have reported that many Rokinon lenses have de-centered opitcs (a quality control problem) and if you get a "new" lens, you should test it. They would notice that when the focus the stars, the stars on one side of the frame might be in focus, but stars on the other side of the frame would be out of focus (indicating a problem with the optical elements inside the lens).