Single-lens translucent (SLT) is a Sony proprietary designation for Sony Alpha cameras which employ a pellicle mirror, electronic viewfinder, and phase-detection autofocus system. They employ the same Minolta A-mount as Sony Alpha DSLR cameras. [1]
Sony SLT cameras have a semi-transparent fixed mirror which diverts a portion of incoming light to a phase-detection autofocus sensor, while the remaining light strikes a digital image sensor. The image sensor feeds the electronic viewfinder, and also records still images and video on command. The utility of the SLT design is to allow full-time phase-detection autofocus during electronic viewfinder, live view, and video recording operation. [2] [3] With the advent of digital image sensors with integrated phase-detection, the SLT design is no longer required to accomplish this goal, as evidenced by cameras such as the Sony NEX-5R, Fujifilm X-100s, and Nikon 1, [4] [5] although the SLT design avoids having pixels unavailable for image formation due to their space on the sensor being occupied by a dedicated phase detection autofocus sensor.
The term "translucent" is a misnomer for the actual SLT design, which employs a pellicle mirror that is not translucent[ citation needed ]. Pellicle mirrors have been used in single-lens reflex cameras from at least the 1960s (see Canon Pellix) and in the Pentax EI2000/Hewlett Packard 912 digital SLR of 2000 which used an optical viewfinder and on-sensor contrast-detection focussing.
Model | Announcement | Megapixels | Sensor | Screen | Built-in flash |
---|---|---|---|---|---|
Sony Alpha 33 | 2010 | 14 MP | APS-C | 3" articulated | (pop-up) |
Sony Alpha 35 | 2011 | 16 MP | APS-C | 3" fixed | (pop-up) |
Sony Alpha 37 | 2012 | 16 MP | APS-C | 2.7" tilting | (pop-up) |
Sony Alpha 55 | 2010 | 16 MP | APS-C | 3" articulated | (pop-up) |
Sony Alpha 57 | 2012 | 16 MP | APS-C | 3" articulated | (pop-up) |
Sony Alpha 58 | 2013 | 20 MP | APS-C | 2.7" tilting | (pop-up) |
Sony Alpha 65 | 2011 | 24 MP | APS-C | 3" articulated | (pop-up) |
Sony Alpha 68 | 2015 | 24 MP | APS-C | 2.7" tilting | (pop-up) |
Sony Alpha 77 | 2011 | 24 MP | APS-C | 3" fully articulated | (pop-up) |
Sony Alpha 77 II | 2014 | 24 MP | APS-C | 3" fully articulated | (pop-up) |
Sony Alpha 99 | 2012 | 24 MP | Full-frame sensor | 3" fully articulated | |
Sony Alpha 99 II | 2016 | 42 MP | Full-frame sensor | 3" fully articulated |
All of the above cameras record 1920x1080 video at 60i/30p (NTSC regions) or 50i/25p (PAL regions), in MPEG-4, AVCHD or H.264 formats. The Alpha 65 and 77 also records video at 50p or 60p, and the Alpha 99II records 4k video at 100 Mbit/s (using XAVC S) with full sensor read-out.
Source: summarised from the full comparison table at DP Review.
A single-lens reflex camera (SLR) is a camera that typically uses a mirror and prism system that permits the photographer to view through the lens and see exactly what will be captured. With twin lens reflex and rangefinder cameras, the viewed image could be significantly different from the final image. When the shutter button is pressed on most SLRs, the mirror flips out of the light path, allowing light to pass through to the light receptor and the image to be captured.
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 mechanisms of a single-lens reflex camera with a solid-state image sensor and digitally records the images from the sensor.
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 30.15 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.
Bridge cameras are cameras that fill the niche between relatively simple point-and-shoot cameras and interchangeable-lens cameras such as mirrorless cameras and single-lens reflex cameras (SLRs). They are often comparable in size and weight to the smallest digital SLRs (DSLR), but lack interchangeable lenses, and almost all digital bridge cameras lack an optical viewfinder system. The phrase "bridge camera" has been in use at least since the 1980s, and continues to be used with digital cameras. The term was originally used to refer to film cameras which "bridged the gap" between point-and-shoot cameras and SLRs.
Sony α is a brand of digital camera. This line has been active since 2006, building upon the Konica Minolta camera technologies, whose assets were acquired by Sony.
Live preview is a feature that allows a digital camera's display screen to be used as a viewfinder. This provides a means of previewing framing and other exposure before taking the photograph. In most such cameras, the preview is generated by means of continuously and directly projecting the image formed by the lens onto the main image sensor. This in turn feeds the electronic screen with the live preview image. The electronic screen can be either a liquid crystal display (LCD) or an electronic viewfinder (EVF).
A pellicle mirror is an ultra-thin, ultra-lightweight semi-transparent mirror employed in the light path of an optical instrument, splitting the light beam into two separate beams, both of reduced light intensity. Splitting the beam allows its use for multiple purposes simultaneously. The thinness of the mirror practically eliminates beam or image doubling due to a non-coincident weak second reflection from the nominally non-reflecting surface, a problem with mirror-type beam splitters. The name pellicle is a diminutive of pellis, a skin or film.
The Micro Four Thirds system is a standard released by Olympus and Panasonic in 2008, for the design and development of mirrorless interchangeable lens digital cameras, camcorders and lenses. Camera bodies are available from Blackmagic, DJI, JVC, Kodak, Olympus, Panasonic, Sharp, and Xiaomi. MFT lenses are produced by Cosina Voigtländer, Kowa, Kodak, Mitakon, Olympus, Panasonic, Samyang, Sharp, Sigma, SLR Magic, Tamron, Tokina, TTArtisan, Veydra, Xiaomi, Laowa, Yongnuo, Zonlai, Lensbaby, Venus Optics and 7artisans amongst others.
A mirrorless camera is a digital camera which, in contrast to DSLRs, does not use a mirror in order to ensure that the image presented to the photographer through the viewfinder is identical to that taken by the camera. They have come to replace DSLRs, which have historically dominated interchangeable lens cameras. Other terms include electronic viewfinder interchangeable lens (EVIL) cameras and compact system cameras (CSCs).
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 α55 is a midrange-level SLT camera, released in August 2010.
The Sony α77 was the flagship for Sony's midrange Alpha SLT camera line.
The Sony α37 or Sony Alpha 37 is a single-lens reflex style digital camera that replaced the SLT-A35 in 2012. However, the Alpha 37 camera features an electronic viewfinder and a translucent mirror. The main advantage of a translucent mirror is that it needn't flip up out of the way when taking a picture in order to expose the sensor, but the camera can focus and capture images simultaneously. Also the viewfinder can be used while video recording or stills/video playback, which is useful for example in bright sunlight. The camera's 15-point autofocus system can be set to single, continuous or automatic and is arranged towards the centre. The 7 fps burst mode is available only in "speed priority" mode but can reach up to 5.5 fps burst rate in combination with any other settings. The A37 is compatible with Sony Bravia Televisions.
The Sony Alpha 57 is a Digital single-lens reflex camera that replaced the A55 in 2012. The camera features an electronic viewfinder and a translucent mirror. The main advantage of a translucent mirror is that it needn't flip up out of the way when taking a picture in order to expose the sensor, but the camera can focus and capture images simultaneously. The camera's 15-point autofocus system can be set to single, continuous or automatic and is arranged towards the centre. The 12-fps burst mode is available only in "speed priority" mode but can reach up to 5.5 fps burst rate in combination with any other settings.
The Sony Alpha 99 was announced by Sony on September 12, 2012. It was the flagship Sony DSLR camera and of the Sony Alpha SLT line until late 2016 when it was replaced by the Sony α99 II.
In Sony digital cameras, the acronym ILCE stands for "Interchangeable Lens Camera with E-mount". In August 2013, Sony announced the first model of the ILCE mirrorless camera with E-mount, electronic viewfinder, contrast-detection autofocus and Multi Interface Shoe, the ILCE-3000. In October 2013, two full-frame E-mount cameras were announced, the ILCE-7 and ILCE-7R.
Announced by Sony on August 24, 2011, and launched alongside its brother the Sony Alpha 77, the Sony Alpha 65 is the top-tier for Sony's midrange Alpha SLT camera line.
The Sony Alpha 77 II (ILCA-77M2), stylized as the Sony α77 II, is an interchangeable-lens camera aimed at the advanced amateur. It replaced the Sony Alpha 77 model in June 2014. It is similar in design to its predecessor, including the use of a SLT transparent mirror and electronic viewfinder.