Following the disastrous M5, the M4 was reintroduced in 1978 as the M4-2 manufactured in Canada, with only detail differences. Manufacture was simplified and largely mechanised, reducing the very high cost of earlier production.

For the first time provision was made from the outset for a motor winder which would also fit the M4-P and M6 (but not the earlier M5). Although smaller than the earlier M2 winder, the Winder M4-2 was still substantial and more than half the size of the camera body.