The lenses make a difference. The Canon EF to R converter will allow you to use your T7 with Canon EF lenses. The adapter will allow you to use EF-S lenses, but the narrower image circle of the EF-S lenses will result in a cropped image.
This is a photograph I took with an aperture of f/5.6; if you enlarge it, you will notice that the image is somewhat fuzzy even though the focus is spot on.
