The Sony α7, α7R, α7S and α7C (the α is sometimes spelled out as Alpha) are four closely related families of full-frame mirrorless interchangeable-lens cameras. The first two were announced in October 2013,[2] the third in April 2014 and the fourth in September 2020. They are Sony's first full-frame mirrorless interchangeable lens cameras and share the E-mount with the company's smaller sensor NEX series.
The α7 II was announced in November 2014, and is the first in the family to revise the original body and ergonomics. The α7C introduced an even more compact form factor, being the smallest full-frame camera with in-body image stabilization.[3] The α7 series is targeted at experienced users, enthusiasts and professionals.[4]
The Sony α7 and α7R have the model numbers ILCE-7 and ILCE-7R respectively. In addition, the α7S, the α7 II, and the α7R II have the model numbers ILCE-7S, ILCE-7M2, and ILCE-7RM2. Sony's new model naming prefix strives to unify model names. "ILC" stands for Interchangeable Lens Camera, followed by an indicator of A-mount "A" or E-mount "E".[5]
Pre-announcement rumours speculated that the new camera would be named "Sony NEX-9".[6]
In 2014/2015, three new models became available forming the second generation of α7 series. They are the α7 II (ILCE-7M2), α7R II (ILCE-7RM2) and α7S II (ILCE-7SM2). Sony continues to produce the first generation models α7 and α7S, even three years after the launch, only the α7 has been discontinued in April 2019.[citation needed]
The basic α7 II model has 24 MP and has manual focus and hybrid autofocus.[citation needed]
The second generation common ground is the newer and improved body design as well as the world's first five-axis sensor-shift image stabilization system for a full-frame ILC. Sony claims that this can compensate a 4.5-stop equivalent of camera shake. In-body stabilization requires no special lens features, and mirrorless system cameras can typically accommodate lenses from any SLR system.[7][8] As an upgrade of the α7, the α7 II has the same 50 Mbit XAVC-S codec as the α7S but lacks 4K video, and the five-axis stabilization is less effective in video mode than that used in the Olympus OM-D E-M1.[9] However, the crop mode used in the α7 II does not incur "very much loss in image quality", unlike that of the Nikon D750.[9]
On 14 June 2015, Hasselblad announced the Lusso, a variant of the Sony α7R marketed by Hasselblad.[citation needed]
The third generation started in 2017, and the fourth was announced in July 2019.[citation needed]
BIONZ is a line of image processors used in Sony digital cameras. It is currently used in many Sony α DSLR and mirrorless cameras. Image processing in the camera converts the raw data from a CCD or CMOS image sensor into the format that is stored on the memory card. This processing is one of the bottlenecks in digital camera speed, so manufacturers put much effort into making, and marketing, the fastest processors for this step that they can.
Sony designs the circuitry of the processor in-house, and outsources the manufacturing to semiconductor foundries such as MegaChips and (mostly) GlobalFoundries, as they currently do not own any fabrication plant capable of producing a system on a chip (SoC).[1] Sony also sources DRAM chips from various manufacturers namely Samsung, SK Hynix and Micron Technology.
BIONZ utilizes two chips in its design. The first chip is an SoC that manages overall functionality of the camera such as SD card storage management, wired connection such as USB and HDMI, and wireless protocols such as Wi-Fi and NFC that are increasingly common on modern Sony α cameras. The BIONZ SoC can be identified by its part number "CXD900xx". The second chip is the ISP (image signal processor). It handles the data directly from the CMOS image sensor, and it is directly responsible for the camera's high-ISO noise characteristics in a low-light environment. The ISP can be identified by the part number "CXD4xxx".
Click here to know more about the History of BIONZ chips in Sony Cameras.
The Sony α (Alpha) cameras, particularly the α7 and α7R models, garnered widespread acclaim from critics and industry experts. DxOMark, a reputable source for camera and lens evaluations, crowned the α7R as the highest ranking full-frame mirrorless camera, with a score of 95 (the same score as the Nikon D800, but one point behind the Nikon D800E). The α7 achieved a score of 90, higher than the Nikon Df and Nikon D4 professional DSLR cameras, and even Sony's own SLT-A99. The Verge rated the cameras 8.3 out of 10, commenting that "It might be a few years before we realize it, but when the DSLR is relegated to a niche status among specialty photographers and full-frame mirrorless cameras dominate the market, we'll have the α7's to thank as the cameras that started it all."[40] EPhotozine which rated the α7 5 stars, meanwhile praised the α7 series' price point for making them "the cheapest full-frame digital cameras currently available" while being lighter and smaller than comparable cameras.[41] It awarded the α7 "Camera of the Year".[42] The α7R was awarded by Imaging Resource as the "Camera of the Year".[43]