The Contax AX is arguably one of the most complex film SLR cameras ever made. It features an autofocus system that allows the use of all available Contax / Yashica (C/Y MM) mount lenses without needing motorization in the lenses themselves. Instead, it's the film plane that moves forward/backward about 10 mm on ceramic steps.

The technical and commercial name for this system is Automatic Back Focusing (ABF). The AF point is visible in the viewfinder on a scale showing the film plane position. Sharpness can also be confirmed with an audible signal (which can be deactivated). For macro photography, however, focusing must be done manually.

The significance of this model becomes evident considering that some photographers owned beautiful and expensive Carl Zeiss lenses, either German or Japanese, in C/Y mount, which were used with previous cameras like the Contax 137 or RTS. Interestingly, the first owner of this camera had 13 different Carl Zeiss T* lenses for this body. Here, the camera is presented with two standard lenses, a Planar and a Tessar (pancake).

The Contax AX should not be confused with its predecessor, the RX, which only had autofocus assistance, not a full AF system.

In addition to its autofocus capabilities, the Contax AX offers automatic program modes, aperture priority, shutter priority, and full manual mode. Light metering is performed by SPD diodes (Silicon Photo Diodes) without memory effect. Due to the ABF autofocus and metering system, only concentric polarizing filters should be used.

The camera supports bracketing (A.B.C. mode) with 3 exposures, which can be relative to a memorized exposure as the base. The viewfinder screens are user-replaceable (with 5 options available), although this operation is quite delicate. The TTL flash syncs automatically in Av mode between 1/60 and 1/200 seconds. In Tv mode, sync options include 1/125 or 1/200, with the possibility of selecting second curtain sync with a dedicated Contax TLA flash.

Multiple exposures (up to 9 overexposures) can be set, and certain functions, such as film rewinding, can be personalized. Dioptric adjustment is easily accessible on the side of the prism, and the viewfinder includes a cover to close the eyepiece. An electronically controlled cable release can be used, and an optional data back can print shooting information between frames and enable interval shooting.

Based on overwhelmingly positive feedback, the Contax AX was particularly favored by nature, portrait, and technical photographers, though less so by action photographers (reportage or sports). Its main advantage, aside from its robust build quality (using high-hardness aluminum and titanium), was undoubtedly the integrated AF system. Being able to use autofocus with nearly any of the 50 Carl Zeiss T* lenses of the new generation was a significant advantage, despite some documented minor constraints with specific lenses.

However, the camera is notably large and heavy and may not be as rugged as competitors intended for more adventurous use. It was also quite expensive, costing over $2000 USD for the body alone upon release.

Today, the camera is housed at the Swiss Museum of Photography in Vevey, Switzerland.