From the earliest days of the Leica, enlargers were an integral part of the system because contact prints from the 24 x 36mm format were viewed as an intermediate step, and not as the end product. Indeed, some of the earliest promotional literature for the Leica I (Model A) highlighted the camera’s ability to capture images of sufficient sharpness and detail to enable large diameter enlargements of superlative quality to be made from “miniature” format negatives.
There are 4 models of the E. Leitz Wetzlar “Box Type Enlarging Apparatus,” one of which is pictured in the July 1928 edition of “Directions for using the Leitz ‘Leica’ Camera.” All but one of these used the same tall, vertical, crinkle-finished, two-section metal housing with a lamp socket and non-detachable power cord emerging from the top. These were diffusion enlargers with opal bulbs, and they all were capable of exposing sheets of photographic print paper in small print sizes. The Flein, built into a vertical box of unspecified construction (probably wood) incorporated a fixed focus 65mm lens and made 3-1/2 x 2-1/2-inch enlargements. The Fleos provided the same print size as the Flein but evidently used a metal housing “with 75-watt opal bulb in detachable metal casing” i.e., the top section. The Filar “Plain daylight enlarger” resembled the Fleos , and had a 65mm lens like the Flein, but it made larger postcard-sized 5-1/2 x 3-1/2-inch prints. The similarly configured Filix also made postcard-sized prints but used a 100-watt bulb. All these units performed admirably according to contemporary users, were beautifully made, and quite durable, but they lacked the flexibility of an adjustable enlarger.