Earlier versions of the Nikon S2 are known as "Chrome Dial S2s" because they feature a chrome shutter speed dial. The S2 was the first Nikon camera to use a standard 24x36mm format. Previous models such as the Nikon S used a slightly smaller 24x34mm format. Upgrades to the S2 also included an improved viewfinder, which was brighter with a 1x magnification. The S2 adopted an aluminum alloy frame, so it was lighter than previous models without compromising durability. It was also easier to change film with the S2 with a single bottom opening key.
The Nikon S2 introduced a film advance lever and rewind lever, which was easier to use compared to the film advance and rewind knobs on previous models. The S2 also featured a top shutter speed of 1/1000th of a second as compared to 1/500th on other Nikon rangefinders. In addition to using the lens to focus, the toothed wheel on the top of the camera was used to focus. The helical focusing is useful for one handed camera operation as the lens in rotated to focus via the camera body instead of requiring the lens elements to rotate in order to focus.
The Nikon S2 also has a unique lens associated with it, which is the 50mm f1.4 Nikkor-S constructed of aluminum. The aluminum 50mm lens was introduced in 1955, and it had a very small production run of about 300 units. It is believed to have been an experimental design for Nikon, perhaps in an effort to produce a lighter weight lens. The entire outer barrel including the filter ring is made of aluminum, as well as many of the internal components. Another noteworthy issue to mention in regards to this experimental lens is that many of the serials numbers of the aluminum version are the same was the chrome version.
The aluminum 50mm lens is lighter than the chrome version with an approximate weight of 4.1 ounces. All of the other specifications of the aluminum version are the same as the standard 50mm f1.4 lenses. The chrome version is very similar to the aluminum lens, but upon closer inspection the finish of the aluminum has less sheen and a different texture. An interesting thing to note about the aluminum lens is that it was sold without documentation of its special feature, so whomever purchased it at the time would have been unaware of its rare status.
Click HERE to view the Nikon S2 with the rare 50mm f1.4 Nikkor-S aluminum lens on the KEH Camera Outlet on eBay.