1965's Canon Pellix is a fairly standard 35mm SLR with one unique gimmick: the viewfinder doesn't black out when the shutter is fired! To manage this, The camera makes use of an ultra thin, semi-transparent pellicle mirror (hence, Pellix) that simultaneously transmits light to the film and to the finder. The mirror is fixed, so it doesn't flip up when the shutter is tripped, and you don't lose sight of your subject during the moment of exposure. The lack of mirror movement also limits vibrations during operation, which might help reduce camera shake a little bit. It's pretty weird when you've used SLR's your entire life, and you're used to the momentary blackout and mirror slap. At first it feels like the camera is broken!
There are a few drawbacks to the pellicle mirror system. Since light entering the camera is effectively split by the mirror, the finder is a bit darker than with a typical SLR. Focusing can be a little difficult in lower light, but it's not horrible with a fast prime lens. I can't imagine using this camera with zooms, though. The mirror also causes less light to be transmitted to the film, resulting in half a stop of light loss, which you need to compensate for if you're using an external meter. I totally forgot to do this, so some of my negatives came out looking a little thin. The mirror is also very fragile since it's so thin, and nearly impossible to clean. If it gets dirty, it can conceivably affect image quality, since it's always between the lens and the film. I bought my Pellix for super cheap because it had a dirty mirror. Image quality still seemed fine, but I was using very wide apertures for most of my shots. Dust and grime on the mirror might affect images when using a narrow aperture.
Shooting with narrow apertures also pretty much gets rid of the pellicle mirror advantage, because the finder still gets very dark when the lens stops down. If you're shooting at f/5.6 or narrower, you may as well be using a tradition mirror. But, for shooting subjects at wide apertures, the Pellix is a fun, gimmicky camera.
Aside from the mirror, the Pellix is a typical SLR camera, with all the basic features you could expect to find on a mechanical camera of the era. There's a standard range of shutter speeds (1-1/1000 plus B), a match-needle exposure meter, and a self-timer/depth of field preview switch. The finder and focusing screen are fixed. The Pellix does feature Canon's QL (quick load) system, which makes loading film extremely simple.
Overall I would not recommend the Pellix to anyone except for collectors or geeks like myself. The finder is just a bit too dark. Pellix finders are also prone to de-silvering, which adds to composing and focusing woes. I had to buy and return three Pellix cameras before I found one that didn't cap at speeds above 1/125th of a second, so their shutters don't seem very dependable. All that said, I still enjoyed using the Pellix, if only for the pellicle mirror novelty. Below are some photos I made with the Pellix using a 50mm f/1.8 Canon lens and Arista EDU 400 film.