The new A57 replaces the A55 in Sony's line of fixed-translucent-mirror SLT cameras. With a number of refinements and some features taken from the new A65, the A57 is poised to take its place as a next-generation, fixed-mirror reflex camera with fast AF, top-quality video and top still-image quality.
16.1 MP APS-C Sensor
The A57 features essentially the same highly regarded 16.1-megapixel Exmor APS HD CMOS sensor as the A55 (and NEX-5N) and combines it with the latest-generation BIONZ imaging engine developed for the A65 and A77 cameras to provide improved image quality, better full HD video and quick operation. The ISO range is from 100 to 16,000.
The A57's built-in flash appears to be the same as the one in the A65, with an ISO 100, GN of 10 (in meters), 3-second recycling and covering an 18mm lens' angle of view.
Translucent Mirror Technology
Sony's Translucent Mirror Technology in the SLT cameras solves some problems inherent in conventional SLRs where the mirror must flip out of the way to make an exposure. Since conventional phase-detection AF systems can't function with the mirror in the up position, they can't provide continuous phase-detection autofocusing during live-view or video operation, and must alternate between focusing and exposing even for non-live-view sequence shooting. Sony's SLT Translucent Mirror Technology eliminates those problems, speeding operation, eliminating mirror vibrations and providing continuous phase-detection AF with eye-level viewing even for video—while saving the complexity and cost of the SLR's moving mirror and the bulk of a pentaprism or pentamirror viewfinder.
Sony A-Mount Lenses
Besides Sony's A-mount lenses, you can use legacy Konica Minolta Maxxum lenses with the A57. Sony currently offers around 30 lenses, from a 16mm ƒ/2.8 fisheye and 11-18mm superwide zoom to a 70-400mm telezoom, including true macro lenses. A new 500mm ƒ/4 supertelephoto is due soon.
SteadyShot INSIDE Stabilization
Like all Sony DSLR and SLT cameras, the A57 features SteadyShot INSIDE sensor-shift image stabilization, which works with all lenses. And you can see the effects in the eye-level electronic viewfinder—an advantage over sensor-shift stabilized conventional DSLRs with their optical viewfinders.
Image Sensor: 16.1-megapixel (effective) Exmor APS HD CMOS Sensor Size: 23.5x15.6mm (APS-C) Lens Mount: Sony A-mount Image Stabilization: Sensor-shift, Super SteadyShot LCD Monitor: 3.0-inch, 921,600-dot TFT Viewfinder: 1.2cm SVGA Tru-Finder Video: AVCHD Progressive v2.0, 1920x1080/60p, 60i & 24p; MP4 1440x1080/30p; 640x480/30p AF System: 15-point, 3 cross-type Shutter Speeds: 1⁄4000 to 30 sec., X-sync up to 1⁄160 sec. Flash: Built-in auto pop-up, GN 10 (in meters, ISO 100); wireless control ISO Settings: 100-16,000 Continuous Firing Mode: 8-12 fps Recording Format: JPEG, RAW, RAW + JPEG Metering: 1200-zone evaluative, CW and spot Storage Medium: SD, SDHC, SDXC, MS Pro Duo, MS PRO-HG Duo Power Source: Rechargeable InfoLITHIUM NP-FM500H battery Dimensions: 5.2x3.8x3.2 in. (body) Weight: 19.0 oz. Estimated Street Price: $700 Contact: Sony, www.sonystyle.com