The Nikon rangefinder cameras and reflex housings

50cm f5 Nikkor and the view

This entry covers reflex housings (sometimes called "mirror boxes") that fit and work on Nikon's series of interchangeable rangefinder cameras. You are also welcome to look at my earlier site on the 500mm (50cm) f5 Nikkor in short mount, one of Nikon's early lenses for its reflex housings [http://www.personal.psu.edu/mwl2/500/500Nikkor.htm]. This is a condensation of a series of articles that appeared earlier in the Nikon Historical Society's Journal.

The entries will cover the six housings shown below. All will fit on a Nikon RF camera and allow infinity focus with their own lenses.

 Kilfitt kilfascope with cable, Novoflex, Panflex II, Panflex model 1, Nikon reflex housing, model I, Nikon Housing model II

Each one has its values and idiosyncrasies.

The Kilfascope was one of Kilfitt's second series housings. It has a forty-five degree angled finder that provides a right-side-up and laterally-correct view similar to Kilfitt’s earlier Repriscope. The mirror is spring-loaded in the up position. Pressing down on a button on the left side of the housing lowers the mirror and a connecting cable plugged into the right side holds the mirror in the correct position. This cable screws into the camera’s cable release socket. Pressing down on the button causes the pin to withdraw, releasing the mirror, followed by the firing of the shutter. It is impossible to get out of sync and the action is as fast as the photographer’s finger, permitting rapid firing and film advancing. Re-lowering the mirror is awkward. The view in the finder is reduced but bright with both the landscape and portrait views outlined by overlapping horizontal and vertical boxes. The camera may be rotated, allowing either view to be used without having to turn the housing on its side. Short-mount lenses included a 90mm f3.5, a 135mm f4, 150mm f4.5, 300mm f5.6 and a 400mm f5.6, still famed for their lightness and sharpness. Many were sold with adaptors for use on Arriflex movie cameras. All came in Leica-thread. Focal lengths 150mm and longer will focus to infinity on a Contax-mount housing as seen below. Unfortunately, their single helical focusing rings tend to shift whenever one closes down the diaphragm. In addition, their focusing helicoids turn in the opposite direction of Nikkor lenses in Nikon mount. Early versions of these lenses had manual diaphragms. Later ones were preset. Kilfitt used rubber bands for its focusing and aperture rings. In many cases these have stretched and no longer fit tightly, or are even missing.  In addition, their back rings are so thick that they get in the way of mounting the reflex housing on a large-based tripod.

The 150mm Kilar lens is particularly sweet: light, compact and it takes 52mm filters.

The 300mm f5.6 Kilar in Leica short-mount. Behind is a Novoflex housing also with a 300mm f5.6 lens. These housings have a Contax bayonet in back and Leica thread in front. Both units work on a Nikon rangefinder camera.

Image: Landscape taken with 300mm Noflexar. Note the vignetting, a problem with all long-focus lenses and the Nikon RF cameras.

The Novoflex housing also came in either a waist-level version or one with a fixed 45 degree finder. The 45 degree finder can be rotated 360 degrees, allowing its use from a variety of positions. The mirror box in the Contax/Nikon mount version, 98mm in depth, is deeper then the Visoflex standard, but it still has a Leica thread front mount. The mirror is spring loaded up. A lever on the right side of the box cocks the mirror. A metal bridge release that mounts on the camera links the shutter release to one of two small buttons, one for the horizontal viewpoint, the other for the vertical setting that, in turn, release the mirror. The camera may be rotated for vertical or horizontal and the viewfinder rotates with it in the same way Nikon’s second housing does. In action, this housing is one of the best designed and integrated, but if one is missing the bridge, fast action is impossible. It is not known if Novoflex ever offered a bridge to fit the Nikon rangefinder cameras. Novoflex offered a special bellows that locked onto the housing using its tripod screw. The bellows has the ubiquitous Leica thread mount and Novoflex sold a wide range of barrel mount lenses to go on this bellows, ranging from 135mm through 300mm. Unfortunately, the bellows must be focused using the right-hand knob, the left hand serving as a lock. This limits action photography.

30cm f5.6 Noflexar mounted on the Novoflex reflex housing and Nikon SP. Note the home-made bridge

Wolfgang Jacobi, designer of the Panflex in his office in the 1930s. {courtesy of Zeiss Historica Society).

In addition, the Contax-mount Novoflex housing can take longer Noflexar lenses that use their original fast-focus pistol grip. The rapid-focus bellows in Leica thread mount will take 240mm Noflexars and longer. The Leica-thread Pistol-grip focuser will handle the early 300mm Noflexars and longer focal lengths. The later breech-lock mount focusers will only mount on the Leitz Visoflex II.

The first model of the Panflex and the Nikon Reflex housing, model 1, side-by-side for comparison. Their operation is almost the same, but the Nikon housing looks like a Leitz PLOOT housing.

The Zeiss Panflex was designed for closeup work by Wolfgang Jacobi, a designer of accessories within the WICO department (WIssenschaftliche COntax Photography or Scientific Contax Photography department). It has the external Contax mount on the front, allowing a wide range of Contax/Nikon mount lenses, 85mm and longer to be mounted. The pre-war version did not have any particular lenses in short mount designed for it. A 135mm f4.5 Tessar in short mount was prototyped but never put into production. To change from landscape to portrait view, one must use one or the other of the two 3/8” tripod sockets provided. The view through the fixed finder is laterally reversed and upside down, making any field work challenging. A cable release attaches underneath the side housing, a coupling cable projects out the top. Pressing on the cable release forces up the mirror, then the connecting cable which, in turn, depresses the camera shutter release.   It is similar to Zeiss’ Flektoskop (also a Jacobi design) in shape, finder, operation and view, but smaller. It has the external Contax mount on the front, allowing a wide range of Contax/Nikon mount lenses, 85mm and longer to be mounted.

The post-war Panflex II follows the general pattern of the first Panflex but with a number of definite improvements. The view is laterally and vertically correct. A plunger behind the connecting cable allows picture taking without a cable and without moving the hand off the camera. Unfortunately, the 115mm f3.5 Panflex Tessar was the only lens officially sold for the post-war version and it is hard to find and expensive. The connecting cable requires a shallow-depth adapter when used on a Nikon. The Panflex II is easy to operate and use. The tripod mount rotates from horizontal or vertical.

Nikon (Model I)

Rare and strange. Waist-level finder and body modeled on the Leitz PLOOT model housing, but cable system follows ideas of Panflex model I with a cable release or “Finger-tip” release screwing in below the side housing. In use, you push up, forcing the mirror up, then the connector cable.  View is upright but laterally reversed. Exchanging the finder-tip release for a cable release is inconvenient. The release delay is adjustable. The body can be rotated horizontal to vertical with spring-loaded lock to set position, but the view does not rotate. Instead, a cross-shaped mask over the ground glass allows both views to be seen. The Nikon housings have the greatest depth of any housings, limiting focal lengths to 180mm and longer except for the bellows-mount 135mm.

Although first mentioned in 1952, it appears that the first Nikon reflex housing did not make it to market until late in 1954. Fewer than 200 may have been sold before Nikon replaced it with the Model II in May 1956.

Nikon (Model II)

This last model housing for the Nikon is rounded and finished in crinkle-black. It takes the same connecting cable as Model I, and one can substitute a cable for the Nikon pistol grips. The socket for the release is on top of side and forward. The socket is threaded for an external cable release but only the Nikon “Finger-tip release” or the special cable release will work without modification due to the long, narrow plunger needed to push up the mirror. Mirror is spring-loaded down but the slightest pressure on the release will cause it to start to rise, shifting focus. The is probably the most awkward and user-unfriendly housing for the RF Nikons. Shutter release delay is adjustable. 45 degree finder is removable. A few 90 degree pentaprism finders were made late in the RF period. Viewer is bright with a plain ground glass and is large enough that taking in the entire screen can be difficult. A button on the left side allows camera rotation with a locking position for vertical and horizontal. View in finder shifts with the rotation.