C-mount lenses provide a male thread, which mates with a female thread on the camera. The thread is nominally 1 inch (25.4 mm) in diameter, with 32 threads per inch (0.794 mm pitch), designated as "1-32 UN 2A" in the ANSI B1.1 standard for unified screw threads. The flange focal distance is 17.526 millimetres (0.6900 in) for a C mount.
Merely to say that a lens is "C-mount" says very little about the lens's intended use. C-mount lenses have been made for many different formats. C-mount lenses are built for the 8 mm and 16 mm film formats and the 1/3", 1/2", 2/3", 1", and 4/3" video formats, which corresponds to a range of image circles approximately from 5 to 22 mm in diameter.
Depending on the format, the design of the lens and its performance will differ considerably. For example, for the 4/3 format, a 12 mm lens is a wide-angle lens and will have a retrofocus design. For the 2/3-inch format, a 12 mm lens is "normal" and can have a simple and fast double Gauss layout. For the 1/3-inch format, a 12 mm lens is long and can have a telephoto design.
Some TV lenses lack provision to focus or vary the aperture, so may not operate properly with film cameras. Also, some TV lenses may have bits that protrude behind the mount far enough to interfere with the shutter or reflex finder mechanisms of a film camera.
Although C-mount lenses have a back focal distance far too short to be used with 35 mm film SLRs or any existing digital SLR (except some mirrorless cameras, e.g. Canon EOS M), they can be mounted on interchangeable-lens mirrorless digital cameras such as the Micro Four Thirds used by Olympus and Panasonic. However, the vast majority of C-mount lenses produce an image circle too small to effectively cover the entire sensor which has approximately 22 mm diagonal, this produces vignetting.[1] The Nikon 1 series and the Pentax Q series can use C-mount lenses without vignetting.
C mount was created by Bell & Howell for their Filmo 70 cine cameras.[2] The earliest Filmos had slightly different mounts, known as A mount, and B mount. C mount was found on Filmo 70 cameras with serial numbers 54090 and higher,[3] probably from about 1926. Soon after, other camera manufacturers adopted the same mount, and it became a de facto standard for 16 mm cine cameras.
CS-mount has a flange focal distance of 12.526 millimetres (0.4931 in),[4][5] compared to 17.526 millimetres (0.6900 in) for a C mount, but is otherwise the same as C-mount, including the fact that lenses for many different formats are made for it. CS-mount lenses are built for the smaller formats, 1/2 inch and down.
ISO 10935:1996, "Optics and optical instruments -- Microscopes -- Interfacing connection type C"
^Lawrenceripsher.com: Switar 26mm f/1.1 Review December 15, 2009, at the Wayback Machine.
^[1] Yahoo Group discussion: Cine Camera Collectors
^[2] Kodak Movie News, Vol. 2, No. 3 (May–June 1954).
^Hornberg, Alexander (2007-02-27). Handbook of Machine Vision. John Wiley & Sons. ISBN9783527610143.
^"CS-Mount | Edmund Optics". www.edmundoptics.com. Retrieved 2018-07-28.
External linksedit
Making Digital Camera Microscope Adapters. The section "Understanding C-Mount and CS-Mount Standard Mechanics, Optics, and Cameras" discusses the standards and custom machining of C-mount apparatus.
. Collection of cine optics and photos of them.
Machine Vision Inspection Technology. Selection of Lens and extension ring/tube for machine vision
C-Mount explained. Explanation of C-mount and CS-mount
January 01, 1970
mount, laser, mount, laser, type, lens, mount, commonly, found, movie, cameras, closed, circuit, television, cameras, machine, vision, cameras, microscope, phototubes, mount12, mount, lens, with, mount, mount, adaptertypescrewflange17, millimetres, 6900, mount. For the laser mount see C mount laser A C mount is a type of lens mount commonly found on 16 mm movie cameras closed circuit television cameras machine vision cameras and microscope phototubes C mount12 mm f 1 2 C mount lens with a C mount to CS mount adapterTypeScrewFlange17 526 millimetres 0 6900 in C mount lenses provide a male thread which mates with a female thread on the camera The thread is nominally 1 inch 25 4 mm in diameter with 32 threads per inch 0 794 mm pitch designated as 1 32 UN 2A in the ANSI B1 1 standard for unified screw threads The flange focal distance is 17 526 millimetres 0 6900 in for a C mount Merely to say that a lens is C mount says very little about the lens s intended use C mount lenses have been made for many different formats C mount lenses are built for the 8 mm and 16 mm film formats and the 1 3 1 2 2 3 1 and 4 3 video formats which corresponds to a range of image circles approximately from 5 to 22 mm in diameter Depending on the format the design of the lens and its performance will differ considerably For example for the 4 3 format a 12 mm lens is a wide angle lens and will have a retrofocus design For the 2 3 inch format a 12 mm lens is normal and can have a simple and fast double Gauss layout For the 1 3 inch format a 12 mm lens is long and can have a telephoto design Some TV lenses lack provision to focus or vary the aperture so may not operate properly with film cameras Also some TV lenses may have bits that protrude behind the mount far enough to interfere with the shutter or reflex finder mechanisms of a film camera Although C mount lenses have a back focal distance far too short to be used with 35 mm film SLRs or any existing digital SLR except some mirrorless cameras e g Canon EOS M they can be mounted on interchangeable lens mirrorless digital cameras such as the Micro Four Thirds used by Olympus and Panasonic However the vast majority of C mount lenses produce an image circle too small to effectively cover the entire sensor which has approximately 22 mm diagonal this produces vignetting 1 The Nikon 1 series and the Pentax Q series can use C mount lenses without vignetting C mount was created by Bell amp Howell for their Filmo 70 cine cameras 2 The earliest Filmos had slightly different mounts known as A mount and B mount C mount was found on Filmo 70 cameras with serial numbers 54090 and higher 3 probably from about 1926 Soon after other camera manufacturers adopted the same mount and it became a de facto standard for 16 mm cine cameras Contents 1 CS mount 2 See also 3 References 4 External linksCS mount editCS mount has a flange focal distance of 12 526 millimetres 0 4931 in 4 5 compared to 17 526 millimetres 0 6900 in for a C mount but is otherwise the same as C mount including the fact that lenses for many different formats are made for it CS mount lenses are built for the smaller formats 1 2 inch and down Combinations C CS and extension adapter Camerabody Extensiontubeadapter Lens Neteffect Focus Viewangle Zoom Exposure C C Normal Normal Normal Normal C CS 5 mm Near sighted Narrower Larger Darker C 5 0 mm 0 20 in C 5 mm Near sighted Narrower Larger Darker C 5 0 mm 0 20 in CS 10 mm Most near sighted Narrowest Largest Darkest CS C 5 mm Far sighted Wider Smaller Brighter CS CS Normal Normal Normal Normal CS 5 0 mm 0 20 in C Normal Normal Normal Normal CS 5 0 mm 0 20 in CS 5 mm Near sighted Narrower Larger DarkerSee also editT mount Lens mount Pentax K mount D mount PL mount S mountReferences editISO 10935 1996 Optics and optical instruments Microscopes Interfacing connection type C Lawrenceripsher com Switar 26mm f 1 1 Review Archived December 15 2009 at the Wayback Machine 1 Yahoo Group discussion Cine Camera Collectors 2 Kodak Movie News Vol 2 No 3 May June 1954 Hornberg Alexander 2007 02 27 Handbook of Machine Vision John Wiley amp Sons ISBN 9783527610143 CS Mount Edmund Optics www edmundoptics com Retrieved 2018 07 28 External links editMaking Digital Camera Microscope Adapters The section Understanding C Mount and CS Mount Standard Mechanics Optics and Cameras discusses the standards and custom machining of C mount apparatus List of some C mount lenses Collection of cine optics and photos of them Machine Vision Inspection Technology Selection of Lens and extension ring tube for machine vision C Mount explained Explanation of C mount and CS mount Retrieved from https en wikipedia org w index php title C mount amp oldid 1192193161, wikipedia, wiki, book, books, library,
