Zenit cameras were the most popular SLR cameras in the Soviet Union. Almost every photographer dreamed of having such a camera since their quality was quite good by Soviet standards, and the features made it possible to photograph without any difficulties.
In contrast to rangefinder cameras, such as FED or Zorki, Zenit cameras allowed to see the image as it will look in the final photograph. The very first cameras, that is, the original Zenit and Zenit C, were copies of Leica cameras with an added mirror mechanism.
Later, from year to year, KMZ continued to produce in fact the same camera but with microscopic changes. And each change made it possible to give a new index to the camera.
That is, we believe that the first few models of these cameras were the best. Starting with the Zenit E, quality began to decline. And in the 90s there was nothing left of the quality of the very first devices made in the early 50s.
But there were attempts to create high-quality and complex (by Soviet standards) cameras for professional photographers. But all these attempts ended in nothing. Such cameras as Start, Zenit Automat, and AM were practically not popular since they were not very high quality but extremely expensive (especially for the Soviet population).