I heard if you rip a blu ray in mkv format it takes it down to 720p. If you then take that mkv and put it on a dvd+r will it be even lower quality? Assuming that that mkv is more than 4.7MB of course.
Taking 720p as 1280x720 pixels and 480i DVD as 720x480 pixels, then a smaller number of pixels cannot contain the same amount of information.