Thanks to advancements in technology, over the past year we saw a significant number of new devices touting their 4K credentials. The now-standard 1080p is a thing of the past in product announcements, present in the specifications sheet as a second-tier option. Even smartphones can now record 4K video (a good example of which is the Samsung Galaxy Note 3), which is an astonishing feat.
The 4K format, used as a catchier moniker for 2160p, only represents a niche at this point, as it has yet to reach a mainstream level of adoption. The inhibitive cost of supporting devices, smart TVs especially, as well as the scarce availability of 4K content contribute to this. But, 4K has also received little attention from camera manufacturers, which have been slow to implement the richer format in their lineups. Sony is among the first to change this, as it just unveiled its 4K-ready A7S full-frame mirrorless offering.
The A7S is part of the A7 lineup, which also includes the entry-level A7 and the high-end A7R. The latter two are designed with photographers in mind, who are looking to replace their full-frame DSLRs without making any of the sacrifices associated with smaller sensors (APS-C, for instance). Sony is the first and only manufacturer to offer full-frame mirrorless cameras on the market.
The A7S, however, is not geared towards photography. The clue lies in the sensor resolution of just 12.2 MP, which is lagging behind virtually every new camera on the market today. You can still snap pictures with it, but I reckon Sony would rather want photographers to buy its impressive A7R instead, or even the less costly A7, for this purpose.
To record 4K video, the A7S uses a whopping 8.3 MP from its sensor. The output resolution is 3840 by 2160 which, according to Sony, makes entire use of the width of the sensor. The new camera comes with an extended ISO range of 50 to 409,600 (normal range is between 100 to 102,400). For 4K recording, users can choose between 24 or 30 frames per second. The upper end of the ISO range matches that of the new Nikon D4s, which does not support 4K.
The A7S can focus in low light up to -4EV (Sony says this only works with F2.0 lenses, when used at ISO 100). It comes with contrast-detection autofocus and 25 autofocus points, the usual tilting-style screen for the series (3-inch TFT, with 0.92 million pixels) and 2.4 MP digital viewfinder. Wi-Fi is also available out-of-the-box, as well as NFC (Near Field Communication), which will work with Xperia smartphones.
Other specs include a fastest shutter speed of 1/8000 of a second (slowest is 30 second), 2.5 FPS burst rate and a battery rating of 320 shots through the viewfinder, or 380 shots using the rear display.
There is no word yet regarding pricing or availability. As is the case with full-frame (mirrorless or DSLR) cameras, do not expect it to be cheap. The entry-level A7 now runs for $1,699 in US.
Sony"s new full-frame A7S mirrorless camera can shoot in 4K