When I look at Canon New F-1 serial numbers and date codes, it seems that in the approximate fifteen year life of the camera as a current model, a lot more production and sales took place in the early years than in the later years. This might be true of many models because the longer a model stays in production, the better the chances that newer models from the same or other manufacturers will have improved technology and compete with it. The Canon F-1 and Nikon F series cameras often lagged behind other newer models during their production runs when it came to new technology but if you wanted a manual focus film SLR with interchangeable finders and motor drive capability, these were your choices. I guess you can add the Pentax LX.