Single-lens translucent (SLT) is a

Sony , commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professional ...

proprietary designation for

Sony Alpha , commonly stylized as SONY, is a Japanese Multinational corporation, multinational conglomerate (company), conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's la ...

cameras which employ a

pellicle mirror 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 ...

electronic viewfinder An electronic viewfinder (EVF) is a camera viewfinder where the image captured by the lens is displayed on a small screen (usually LCD or OLED) which the photographer can look through when composing their shot. It differs from a live preview ...

, and

phase-detection autofocus An autofocus (or AF) 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 syste ...

system. They employ the same

Minolta A-mount was a Japanese manufacturer of cameras, camera accessories, photocopiers, fax machines, and laser printers. Minolta Co., Ltd., which is also known simply as Minolta, was founded in Osaka, Japan, in 1928 as . It made the first integrated autofocu ...

as Sony Alpha DSLR cameras. Sony SLT cameras have a semi-transparent fixed mirror which diverts a portion of incoming light to a

sensor, while the remaining light strikes a

digital image sensor An image sensor or imager is a sensor that detects and conveys information used to make an image. It does so by converting the variable attenuation of light waves (as they refraction, pass through or reflection (physics), reflect off objects) in ...

. 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 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 ...

, and video recording operation. 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 The Nikon 1 series is a discontinued camera line from Nikon, originally announced on 21 September 2011. The cameras utilized Nikon 1-mount lenses, and featured 1" CX format sensors. The series included the Nikon 1 V1, J1, J2, and S1 with a ...

, 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 In the field of optics, transparency (also called pellucidity or diaphaneity) is the physical property of allowing light to pass through the material without appreciable scattering of light. On a macroscopic scale (one in which the dimensions a ...

" is a misnomer for the actual SLT design, which employs a

that is not translucent. Pellicle mirrors have been used in

single-lens reflex camera A single-lens reflex camera (SLR) is a camera that typically uses a mirror and prism system (hence "reflex" from the mirror's reflection) that permits the photographer to view through the lens and see exactly what will be captured. With twin le ...

s from at least the 1960s (see

Canon Pellix The Canon Pellix is a manual-focus single-lens reflex (SLR) camera released in 1965 that uses a stationary half-silvered mirror behind which a metering cell is raised during light level metering. The First Canon with TTL Canon suddenly switche ...

) and in the Pentax EI2000/Hewlett Packard 912 digital SLR of 2000 which used an optical viewfinder and on-sensor contrast-detection focussing.

List of SLT cameras

All of the above cameras record 1920x1080 video at 60i/30p (NTSC regions) or 50i/25p (PAL regions), in MPEG-4,

AVCHD AVCHD (Advanced Video Coding High Definition) is a file-based format for the digital recording and playback of high-definition video. It is H.264 and Dolby AC-3 packaged into the MPEG transport stream, with a set of constraints designed around t ...

H.264 Advanced Video Coding (AVC), also referred to as H.264 or MPEG-4 Part 10, is a video compression standard based on block-oriented, motion-compensated coding. It is by far the most commonly used format for the recording, compression, and distr ...

formats. The Alpha 65 and 77 also records video at 50p or 60p, and the Alpha 99II records 4k video at 100Mbit/s (using XAVC S) with full sensor read-out. Source: summarised from th
full comparison table at DP Review

References

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List of SLT cameras

See also

References