is the current crop. The "main" difference is the newer units have wifi capability which you might not need. There may be some sublet differences in the imaging sensors, but (in my opinion) that's more about marketing than technology.
While I appreciate the lighting environment description, I would strongly suggest investigating improving the light. We don't know what that "overhead light" is in your room or its proximity to what you want captured to video. It could be as simple as a couple of clamp lights or a couple of soft boxes... Consider reading up on "Three point lighting". Low-end, entry level camcorders with small lens diameter and small imaging chip just can't do well under mediocre or poor lighting conditions. That which works well for your eyes will be at the hairy edge of the camera's capabilities.
I want to shoot myself writing in pencil into a school notebook. This would be indoors, at my desk, with the camera above me pointed down at the paper, so like a first-person perspective. No special lights except the overhead light of the room.
These would be instructional videos.
Vi Hart does something similar but with a sharpie. She uses a Canon Vixia M40. But this camera is discontinued.
Does the M50 or M500 supersede the M40 and so would be a comparable or better substitute? Since the M-series seems to be dead, what about the still-in-production R-series such as the R52 or R62? Is the main difference the image sensor size? Would this make a difference for my purpose?
Thank you.

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