Twin lens reflex.
I’d never considered one until recently. When I resumed shooting film and began exploring eBay, TLR’s looked interesting. My first acquisition was the Yashica-Mat LM.
First impressions are of a tank of a camera. It’s all metal and very heavy. Focusing is done on a ground glass screen on the top of the camera. A magnifying loupe flips up to aid with detailed focus. The entire front of the camera moves in and out using a knob on the left side.
LM stands for light meter; the YashicaMat uses an uncoupled selenium meter which reads in EV. A mechanical computer built into the focus knob translates EV into shutter/aperture combinations. Shutter speed and f-stop are adjusted with small knobs on either side of the lenses and visible in a small window on top. Film advance is via a crank on the right side which also cocks the shutter. While smooth to use, this does preclude double exposing, whether intentional or inadvertent.
It uses 120 roll film, taking 12 6×6 exposures per roll. Mine came ready to roll right out of the box with only a quick superficial cleaning.
As an experienced manual camera user I had no trouble figuring it out, or so I thought. I mis-read the exposure computer and overexposed half of my first roll.
Once I learned the controls, the results were very nice. This one is a current favorite shooter.