The Four Thirds System is a standard created by Olympus and Eastman Kodak for digital single-lens reflex camera (DSLR) and mirrorless camera design and development.
The EF lens mount is the standard lens mount on the Canon EOS family of SLR film and digital cameras. EF stands for "Electro-Focus": automatic focusing on EF lenses is handled by a dedicated electric motor built into the lens. Mechanically, it is a bayonet-style mount, and all communication between camera and lens takes place through electrical contacts; there are no mechanical levers or plungers. The mount was first introduced in 1987.
An autofocus optical system uses a sensor, a control system and a motor to focus on an automatically or manually selected point or area. An electronic rangefinder has a display instead of the motor; the adjustment of the optical system has to be done manually until indication. Autofocus methods are distinguished as active, passive or hybrid types.
A digital single-lens reflex camera is a digital camera that combines the optics and the mechanisms of a single-lens reflex camera with a digital imaging sensor.
A lens mount is an interface – mechanical and often also electrical – between a photographic camera body and a lens. It is a feature of camera systems where the body allows interchangeable lenses, most usually the rangefinder camera, single lens reflex type, single lens mirrorless type or any movie camera of 16 mm or higher gauge. Lens mounts are also used to connect optical components in instrumentation that may not involve a camera, such as the modular components used in optical laboratory prototyping which join via C-mount or T-mount elements.
The Canon FD lens mount is a physical standard for connecting a photographic lens to a 35mm single-lens reflex camera body. The standard was developed by Canon of Japan and was introduced in March 1971 with the Canon F-1 camera. It served as the Canon SLR interchangeable lens mounting system until the 1987 introduction of the Canon EOS series cameras, which use the newer EF lens mount. The FD mount lingered through the release of the 1990 Canon T60, the last camera introduced in the FD system, and the end of the Canon New F-1 product cycle in 1992.
Advanced Photo System type-C (APS-C) is an image sensor format approximately equivalent in size to the Advanced Photo System film negative in its C ("Classic") format, of 25.1×16.7 mm, an aspect ratio of 3:2 and Ø 31.15 mm field diameter. It is therefore also equivalent in size to the Super 35 motion picture film format, which has the dimensions of 24.89 mm × 18.66 mm and Ø 31.11 mm field diameter.
The M42 lens mount is a screw thread mounting standard for attaching lenses to 35 mm cameras, primarily single-lens reflex models. It is more accurately known as the M42 × 1 mm standard, which means that it is a metric screw thread of 42 mm diameter and 1 mm thread pitch.
The M39 lens mount is a screw thread mounting system for attaching lenses to 35 mm cameras, primarily rangefinder (RF) Leicas. It is also the most common mount for Photographic enlarger lenses.
The Sigma SA-mount is a lens mount by the Sigma Corporation of Japan for use on their autofocus single-lens reflex and mirrorless cameras. It was introduced with the SA-300 in 1992. Originally, the SA-mount was a dual-bayonet mount with inner (SA-IB) and outer (SA-OB) bayonets, the latter being a feature intended to mount heavy telephoto lenses, but never utilized by Sigma and consequently dropped with the release of the SD14 in 2007.
Lens speed refers to the maximum aperture diameter, or minimum f-number, of a photographic lens. A lens with a larger than average maximum aperture is called a "fast lens" because it can achieve the same exposure as an average lens with a faster shutter speed. Conversely, a smaller maximum aperture is "slow" because it delivers less light intensity and requires a slower (longer) shutter speed.
This article is about photographic lenses for single-lens reflex film cameras (SLRs) and digital single-lens reflex cameras (DSLRs). Emphasis is on modern lenses for 35 mm film SLRs and for DSLRs with sensor sizes less than or equal to 35 mm ("full-frame").
A telecompressor or focal reducer is an optical element used to reduce focal length, increase lens speed, and in some instances improve optical transfer function (OTF) performance. It is also widely known under the name “Speed Booster”, which is the commercial name of a line of telecompressors by the manufacturer Metabones. Popular applications include photography, videography, and astrophotography. In astrophotography, these qualities are most desirable when taking pictures of nearby large objects, such as nebulae. The effects and uses of the telecompressor are largely opposite to those of the teleconverter or Barlow lens. A combined system of a lens and a focal reducer has smaller back focus than the lens alone; this places restrictions on lenses and cameras that focal reducer might be used with.
The Panasonic Lumix DMC-G1 was the first digital mirrorless interchangeable-lens camera (MILC) adhering to the Micro Four Thirds system design standard. The G1 camera is similar to the larger Four Thirds system format DSLR cameras, but replaces the complex optical path needed for the optical viewfinder with an electronic viewfinder EVF displaying a live view image directly from the sensor. Eliminating the mirror box and optical viewfinder allows for smaller and lighter camera bodies, while the less complex optical path also allows for smaller, lighter lens designs.
The Samsung NX-mount is the lens mount used on NX series mirrorless interchangeable lens cameras by Samsung. The mount was first implemented in the Samsung NX10, and Samsung initially referred to the NX line as 'hybrid digital cameras', citing their combination of attributes of both DSLR and compact cameras.
A mirrorless camera is a photo camera featuring a single, removable lens and a digital display. The camera does not have a reflex mirror or optical viewfinder like a digital single-lens reflex (DSLR) camera, but may have an electronic viewfinder. Many mirrorless cameras retain a mechanical shutter. Like a DSLR, a mirrorless camera accepts any of a series of interchangeable lenses compatible with its lens mount.
The E-mount is a lens mount designed by Sony for their NEX and ILCE series of camcorders and mirrorless cameras. The E-mount supplements Sony's α mount, allowing the company to develop more compact imaging devices while maintaining compatibility with 35mm sensors. E-mount achieves this by:
The Sony α NEX-5 is a digital camera launched on 11 May 2010. It is a mirrorless interchangeable lens camera with the body size of a larger model fairly compact point-and-shoot camera with a larger sensor size (APS-C) comparable to that of some digital single-lens reflex cameras. Its major competitors in the market are the cameras based on the micro 4/3 standard created by Panasonic and Olympus, and a few low end Canon, Nikon, and even Sony α DSLRs. The NEX-5 shoots 14.2 megapixel stills and has a 7 frame/s continuous shotmode. It has the capability to shoot 1920×1080i at 60 frame/s in AVCHD or 1440×1080p at 30 frame/s in MPEG4. The NEX-5 was replaced by the 16 megapixel NEX-5N in August 2011.
The Pentax Q series is a series of mirrorless interchangeable-lens cameras made by Pentax and introduced in 2011 with the initial model Pentax Q. As of September 2012, it was the world's smallest, lightest interchangeable lens digital camera. The first models used a 1/2.3" back-illuminated sensor CMOS image sensor. The Q7, introduced in June 2013, uses a larger 1/1.7" type sensor. The Q system is now discontinued.
The Samsung NX series was a series of APS-C mirrorless interchangeable-lens cameras with Samsung NX lens mounts from Samsung Electronics, introduced in 2010.
