BNCR mount
Encyclopedia
BNCR is a lens mount
developed by Mitchell
for use with their REFLEX 35 mm movie camera
s. It was an update of the BNC mount done to accommodate the reflex viewer in the later cameras. BNC mount lenses cannot be used in reflex Mitchell cameras as they will hit and damage the reflex viewer, which, in various versions, was a pellicle mirror or a rotating mirror. The abbreviation stands for "Blimped News Camera Reflex", which meant that it is a 35 mm camera originally intended for news reporting but included a blimp housing for sound stage shooting plus a reflex viewer to allow the camera operator to view the action through the lens while filming. The reflex option was only added in 1967, while the blimp option (thereby converting an NC, "Newsreel Camera", into a BNC, "Blimped Newsreel Camera") was available at the camera's introduction in 1934. The lens mount is not identical across all variants - thus there is a marked difference between a BNC and BNCR mount, for instance. BNCR is only the current convention as it was the last version of the camera and in relatively current use through until the 1990s. The mount contains four pronged flanges only one of which contains a notch towards the center. This notch is used to align the mount to a locating pin located approximately 45 degrees clockwise from the top of the camera's lens mount. This radial indexing is of particular importance when shooting an anamorphic format (CinemaScope or Panavision, or equivalent). The mount is locked into place using a friction locking ring which, in conjunction with the four prongs of the flange, creates a very strong lens seating. The quality of this design has been a key influence in the design of the Arri PL
and Panavision mount
, both of which are the main film camera mounts in use today, and both of which have four-pronged flanges oriented based on locating pin-notch combinations. The Arri PL mount in particular is very similar in appearance to the BNCR mount, the only immediately apparent difference being the ability to seat any of the four notched prongs against the locating pin. (The flange focal distance and diameter also differ.)
With the slow obsolescence of the Mitchell cameras, which likely took so long because they were so well regarded in mechanical design aspects, such as their steady movement registration and strong mounts, the mounts have gradually become less common in the past two decades, but remained an option for third party cameras produced as recently as the 1980s. Many of the cameras are still in usage in fields such as animation. Though the mount is not quite as common today, it is still very well regarded in the field.
Lens mount
A lens mount is an interface — mechanical and often also electrical — between a photographic camera body and a lens. It is confined to cameras where the body allows interchangeable lenses, most usually the single lens reflex type or any movie camera of 16 mm or higher gauge...
developed by Mitchell
Mitchell
Mitchell may refer to:* B-25 Mitchell, an American World War II-era bomber aircraft* Billy Mitchell Award, a Civil Air Patrol Cadet Program award* Mitchell , an automobile built in Racine, Wisconsin from 1903-1923...
for use with their REFLEX 35 mm movie camera
Movie camera
The movie camera is a type of photographic camera which takes a rapid sequence of photographs on strips of film which was very popular for private use in the last century until its successor, the video camera, replaced it...
s. It was an update of the BNC mount done to accommodate the reflex viewer in the later cameras. BNC mount lenses cannot be used in reflex Mitchell cameras as they will hit and damage the reflex viewer, which, in various versions, was a pellicle mirror or a rotating mirror. The abbreviation stands for "Blimped News Camera Reflex", which meant that it is a 35 mm camera originally intended for news reporting but included a blimp housing for sound stage shooting plus a reflex viewer to allow the camera operator to view the action through the lens while filming. The reflex option was only added in 1967, while the blimp option (thereby converting an NC, "Newsreel Camera", into a BNC, "Blimped Newsreel Camera") was available at the camera's introduction in 1934. The lens mount is not identical across all variants - thus there is a marked difference between a BNC and BNCR mount, for instance. BNCR is only the current convention as it was the last version of the camera and in relatively current use through until the 1990s. The mount contains four pronged flanges only one of which contains a notch towards the center. This notch is used to align the mount to a locating pin located approximately 45 degrees clockwise from the top of the camera's lens mount. This radial indexing is of particular importance when shooting an anamorphic format (CinemaScope or Panavision, or equivalent). The mount is locked into place using a friction locking ring which, in conjunction with the four prongs of the flange, creates a very strong lens seating. The quality of this design has been a key influence in the design of the Arri PL
Arri PL
Arri PL is a lens mount developed by Arri for use with both 16 mm and 35 mm movie cameras. The PL stands for "positive lock". It is the successor mount to the Arri bayonet; however, unlike the bayonet mount, it is incompatible with older Arri-mount lenses, due to the larger diameter...
and Panavision mount
PV mount
A PV mount is a lens mount developed by Panavision for use with both 16 mm and 35 mm movie cameras. It is the only mount offered with Panavision cameras and Panavision-designed lenses, and since the company only rents its equipment, this is likely to remain an exclusive arrangement for the time being...
, both of which are the main film camera mounts in use today, and both of which have four-pronged flanges oriented based on locating pin-notch combinations. The Arri PL mount in particular is very similar in appearance to the BNCR mount, the only immediately apparent difference being the ability to seat any of the four notched prongs against the locating pin. (The flange focal distance and diameter also differ.)
With the slow obsolescence of the Mitchell cameras, which likely took so long because they were so well regarded in mechanical design aspects, such as their steady movement registration and strong mounts, the mounts have gradually become less common in the past two decades, but remained an option for third party cameras produced as recently as the 1980s. Many of the cameras are still in usage in fields such as animation. Though the mount is not quite as common today, it is still very well regarded in the field.
Technical specifications
- Flange focal distance: 61.468 mm
- Diameter: 68.00 mm
- Cameras:
- 35 mm Mitchell NC, Mitchell NCR, Mitchell FC, Mitchell FCR, Mitchell BNC, Mitchell BNCR, Mitchell S35R, Arri 35BL3, Cinema Products XR35, Cinema Products CP35, Fries 435, IMAGE 300, Moviecam SuperAmerica, Moviecam Compact, PhotoSonics 4ER, PhotoSonics 4ML, Ultracam