Process Cameras were all that way. Two cranks, one moves copyboard the other moves lens board. The film (think paper) plane is fixed. Some were vertical and you had to stand on a stool to look down at it. Most were horizontal and the vacuum back was at a comfortable table level when open. The ground glass at eye level. There were tape measures that the cranks were tied to that indicated percent enlargement/reduction. You just moved the cranks until both indicated the same ... then you were in focus. You could use the ground glass to calibrate the tapes. But most of the time you dialed in and shot.