Ronkonkoma, NY—Sigma Corporation announced that the sd Quattro H mirrorless camera is its first model to feature the newly developed APS-H-size (26.7×17.9mm) Foveon X3 Quattro direct image sensor with 51-megapixel-equivalent resolution.
Featuring the Sigma SA mount, the camera is compatible with all of the Sigma Global Vision lenses in the Contemporary, Art and Sports lines. In DC crop mode, which is automatically activated when DC lenses are attached, it’s possible for users to take full advantage of their lens assets.
Foveon X3 Quattro Sensor
Leveraging the light absorption characteristics of silicon, the camera’s Foveon X3 Quattro sensor comprises three layers of photodiodes, each at a different depth within the silicon and each corresponding to a different RGB color.
The sensor does not require a low-pass filter to correct the interference caused by a color filter array, so it is able to take full advantage of the information carried by light, including 100% of the data for blue, green and red in each of its three layers. As a result, it is said to generate up to twice the resolution data of sensors using a Bayer filter.
In addition, two TRUE (Three-layer Responsive Ultimate Engine) III image processors handle data from the image sensor “at extremely high speed.” The camera is compatible with the DNG format as well as the RAW format, using 14-bit (16,384 gradations) signal processing to convert the analog output signal to digital results in photographic data “with fine gradations that effectively represent the smooth, natural gradations of the original subject.”
The RAW data uses lossless compression that prevents image degradation. The camera can shoot continuously for up to 8 images in RAW format.
Sigma also added the new Super-Fine Detail (SFD) exposure mode to bring out the full performance of the Foveon X3 Quattro sensor. One push of the shutter generates seven different exposures, creating RAW data in the X3I file format. 
Using this data with the Sigma Photo Pro software package, photographers can create noiseless images with an extensive dynamic range. The camera can also process RAW data into JPEGs without the need for a computer. Users can adjust the exposure correction, white balance, color mode and aspect ratio while viewing the photographs on the LCD monitor.
Sigma sd Quattro H AF System
Sigma’s sd Quattro H uses a combination of two AF detection methods: phase-detection AF for speed and contrast-detection AF for focusing accuracy. Single AF mode can be used for everyday photography, while continuous AF mode is for focusing on moving objects.
Other AF modes are also available: 9-point selection AF lets users select from nine focus frames; free movement AF allows users to select the focus frame with high precision; face-detection AF detects human faces and prioritizes focusing on them; and the AF-assist light makes AF possible even in low light.
In addition, the focus-peaking function puts a colored outline (white, black, red, yellow) around the subject in the viewfinder for confirmation of the person or object in focus.
Also featured is a 2.36MP electronic viewfinder with near-100% viewfinder coverage and a 1.09x magnification. Using a switch next to the viewfinder, users can toggle between displaying the image in the EVF and the monitor. In auto mode, the camera automatically switches to the viewfinder display when the user is looking through it and to the monitor when not.
In addition to the 1.62MP, 3-inch LCD main monitor, the rear of the camera features a sub-monitor that displays the number of remaining shots on the SD card, shutter speed, aperture value and ISO level.
Additional sd Quattro H Features
Additional features include: an electronic level; a magnesium alloy body with a dust- and splashproof design; a dust protector on the lens mount; a quick set button that provides access to the quick set menu for fast adjust of commonly used settings while looking through the EVF; color modes; monochrome options; a custom bracketing display; a USB 3.0 micro B port; and a mini HDMI Type C port.
The Sigma sd Quattro H has a suggested retail price of $1,199. sigmaphoto.com
