Exposure: Automatic (selenium cell)
Approx. date of manufacture: 1960
Approx. original price: $210
Keystone interests me because it's another camera company that disappeared almost without a trace. You can still find plenty of examples of them in the fossil record, but almost no recorded history.
Here's what I know about them. They began in 1919 and were based in Boston. They were primarily known for movie equipment and sold a long line of cameras and projectors and accessories. They were purchased by Berkey Marketing in the mid-60s (the same outfit that aquired Simmon-Omega), which went belly-up in the late 80s. As far as I know, the brand name is dormant.
This particular model is my father's, and when I was growing up, it was the "serious" camera. Metal housing, pistol grip, zoom lens, and a live diaphram connected to the onboard light meter. Great machine. My father ran thousands of feet of film through it.
So here goes. This is a Reflex camera, which means you see your image through the same lens that the film is looking through; there's no viewfinder lens located anywhere else. How useful that is depends largely on how close you are to the subject, because the discrepancy between your line of sight and the film's line of sight gets larger as you approach your subject. Even if you don't do close-ups, it's good for seeing things like flare (unwanted light reflections in the lens itself).
Like many makers, Keystone made several nearly-identical models with just a few differences between them. This was the "Horizon" series. The K-12 was the top model. The K-10 was the same but had a separate viewfinder instead of reflex, and cost $180 new. The K-8 was a K-10 but with manual zoom instead of power. In addition, the K-8 had two lens options: the focusing ƒ/1.8 was the De Luxe model, $140; the fixed-focus ƒ/1.8 was the 8C and was $10 less.
I have the owner's manual for this camera available on my manuals page.