LEICA "NULL-SERIE" REPLICA

In the fall of 2000, Leica Camera AG unveiled a new edition of the Leica "Null-Serie" camera at the Photokina trade show in Cologne, Germany²⁶⁹. The camera was listed under catalog number of 10500²⁷⁰.

Looking through the viewfinder, which could be folded down and featured a lens with etched crosshairs and a small swing-in sight, the viewer saw the subject and needed to adopt a different position for holding the camera²⁶⁹. The camera should have been held 25 to 30 cm away from the eyes and oriented so that the crosshairs on the viewfinder lens were centred on the tip of the sight²⁶⁹. This alignment helped define the picture area²⁶⁹.

When the camera was placed in its leather case, the carrying strap, measuring 50 to 60 cm in length, helped maintain the right distance from your eyes²⁶⁹. Additionally, it significantly increased the stability of the camera when held at arm's length²⁶⁹.

The shutter speed knob allowed the selection of five different exposure times²⁶⁹. Unlike modern cameras, the numbers on the perforated disc inside the knurled ring did not directly indicate exposure times in fractions of a second²⁶⁹. Instead, these numbers represented the slit width in millimetres between the two shutter curtains needed to achieve the desired exposure time²⁶⁹. The numbers were as follows²⁶⁹:

• 2mm width of slit / shutter speed setting = 1/500th of a second³³⁷
• 5mm width of slit / shutter speed setting = 1/200th of a second³³⁷
• 10mm width of slit / shutter speed setting = 1/100th of a second³³⁷
• 20mm width of slit / shutter speed setting = 1/50th of a second³³⁷
• 50mm width of slit / shutter speed setting = 1/20th of a second³³⁷

For exposure times longer than 1/20th of a second, the photographer should have set the shutter speed to 1/20th of a second and switched the exposure setting from "M" (for "Momentaufnahme," which means instantaneous exposure) to "Z" (for "Zeitaufnahme," meaning time exposure)²⁶⁹. With the "Z" setting, the shutter would remain open as long as the shutter release button was pressed²⁶⁹.

The settings on the shutter speed button could have only been selected when the shutter was slightly tensioned²⁶⁹. These settings could have been adjusted when the shutter was either fully tightened or completely released²⁶⁹. To position the shutter correctly, the winding knob must have been turned until the inner red dot on the disk of the setting button was aligned exactly to the left of the index line²⁶⁹. In this specific shutter position, the first shutter curtain was not on its take-up drum; instead, it was completely in front of the film gate²⁶⁹. This allowed the shutter curtain to be freely moved to set the desired slit width²⁶⁹.

At this stage, you could press down on the knurled ring of the setting knob²⁶⁹. When the setting was made correctly, a silver pin located beneath the button rose into the desired hole in the disk, allowing the knurled ring to snap back up²⁶⁹. Only then could the shutter be fully wound, which also advanced the film by one full frame²⁶⁹.

The choice of exposure times was heavily influenced by the desired sharpness of a photograph²⁶⁹. Longer exposure times could lead to blurring, while the aperture setting limited the amount of light that entered the camera²⁶⁹. This also affected the depth of field, which refered to the range within the photograph that appeared sharp—both in the foreground and background relative to the subject²⁶⁹.

The parts of the subject that were at the selected focus distance were always depicted with the greatest sharpness²⁶⁹. This highest level of sharpness decreased gradually in front of and behind the set distance, creating an area still perceived as sharp by the human eye despite a slight degree of blur²⁶⁹. This area of acceptable sharpness, known as depth of field, was generally distributed approximately one-third in front of the focus point and two-thirds behind it²⁶⁹. Additionally, the depth of field increased as the aperture became smaller²⁶⁹.

The black numbers on the nickel-plated exposure counter, marked in intervals of five, indicated the number of exposures made²⁶⁹.

The combined film advance mechanism and shutter winder had a unique characteristic²⁶⁹. Similar to the original models, the leather cap must have been placed on the lens each time before advancing the film to prevent light from entering²⁶⁹. This precaution was  necessary because, in the "Null-Serie" Leicas, the focal plane shutter curtains that created the slit did not have self-capping features, unlike those in later models²⁶⁹.

To rewind the film, one should set the rewind lever to "R" (for "Rückspulen" - rewind)²⁶⁹. Additionally, one  must continuously pressed the shutter release button to disengage the film advance mechanism²⁶⁹. 

The baseplate was attached to the right side of the body using a slim pin and was opened and closed with a toggle fastener on the left side²⁶⁹. The original "Null-Serie" Leica featured a 7x1 mm (metric) tripod socket, similar to the ¼-inch tripod socket found on the new edition²⁶⁹.With the introduction of the Leica I Model A, cameras that featured lenses calibrated in meters were equipped with baseplates that had the 3/8-inch "German" tripod socket²⁶⁹. Conversely, cameras with lenses calibrated in feet typically had baseplates with a ¼-inch tripod socket, instead of the 7x1 mm size²⁶⁹.