I wonder why it is that a camera like the original Pentax gets so much appreciation, but more innovative and important cameras rarely get due credit. Despite being marketed as revolutionary, the Pentax didn't actually introduce anything new to the SLR market. It was really just a tiny a step combining a couple of previously introduced features, and it was still missing several key features of the "modern" 35mm SLR.

The Nikon F does get a lot of praise, and rightly so. Correct me if I'm wrong, but the F was the first SLR with the "proper" combination of features we'd take for granted in any SLR since, it has several features that are absent from the Pentax such as a self resetting frame counter, a non-revolving shutter dial (with all speeds on one dial), and automatic diaphragm operation. The only thing it was missing was TTL metering.

Speaking of TTL metering, Topcon is usually ignored in favor of the Pentax Spotmatic for some reason. Topcon introduced fully coupled open aperture metering, whereas the Spotmatic used a simpler stop down metering. Although stop down metering was popular on cheap cameras for years to come, even Pentax realized that open aperture metering was where it was at.

The Konica F was the first SLR with a 1/2000 shutter speed, and perhaps the first with a metal, vertical travel focal plane shutter, which became near universal on SLRs later. It is rarely mentioned when discussing milestones in SLR design. Although it was not a sales success, it is also not an obscure rarity like say the Gamma Duflex which often gets credit today for being a particularly innovative design.

Though the Duflex contained important features such as an instant return mirror, an automatic diaphragm, and eye level viewing - it was somewhat lacking in execution. Eye level viewing was provided by an arrangement of mirrors rather than a pentaprism for instance. It bears little resemblance to the subsequent SLRs in design, and few were made.

The Edixa Reflex of 1954 was perhaps the SLR that set the layout for most SLRs to come. It featured right hand lever wind (on the top of the camera) a rewind button on the bottom of the camera, a (interchangeable) pentaprism viewfinder, and the ASA reminder dial around the rewind knob. Unlike some influential or innovative cameras that were unsuccessful in the marketplace and consequentially rare, the Edixa SLRs were produced for years and are hardly rare or unusual.

Are there other 35mm SLR cameras which are overlooked in favor of more popular brands and models?