The basic concept of Sony's DEV-3 and DEV-5 binoculars is that they reduce the need for photographers shooting birds, wildlife, and sports action to carry two separate devices, one intended for immediate viewing, and the other for image capture. Instead, a single device can be used both to get an up-close view of your subject, and to capture high-res still images and high-definition video. Better still, there's no time lost in reframing the scene as you switch back and forth between separate devices. Courtesy of twin lenses, the DEV-3 and DEV-5 not only offer separate left and right views, unlike some past digital binocular models from competitors, but also take advantage of this to provide true 3D video capture. (Curiously, 3D still capture isn't possible, however).

Both the DEV-3 and DEV-5 share the same basic design, but with a few important differences. Most notably, the Sony DEV-5 adds a built-in GPS receiver that allows it to tag images and video clips as they're saved, marking each with the location at which they were recorded. Compatible software such as the bundled Picture Motion Browser can then use this to indicate the shooting locations or display thumbnails on a map. The GPS functionality is also used to offer a map display function, although it isn't currently clear as to what level of detail or coverage this provides.

Front (left) and rear (right) views of the Sony DEV-3 / DEV-5 binoculars. Photos provided by Sony Electronics Inc.

Although both binoculars feature the same optics with a still image magnification range from 0.9x to 10x, the DEV-5 adds an additional digital zoom function that can double this to an effective 20x magnification. The DEV-5 also has a more expansive product bundle, which includes a lens cover, finder cap, large eye cups, a carrying case and a neck strap. The Sony DEV-3 and DEV-5 feature Sony G-branded optics with a variable aperture from F1.8 to F3.4 across the zoom range, and include the company's Optical SteadyShot image stabilization with Active mode, which provides a greater degree of correction than the standard Optical Steadyshot. Note, though, that Active mode is only available at wide angle when viewing or shooting in 3D mode, and you must switch to 2D mode to gain Active mode at telephoto. Either binocular model is usable in light down to 11 lux.

Behind their optics, each model has a pair of Sony Exmor R backside-illuminated CMOS image sensors, each with a 4.5mm diagonal and a total resolution of approximately 4.2 megapixels. Data from these twin sensors is handled by a Sony Bionz-branded image processor, and can provide JPEG still images at resolutions up to an interpolated 7.1 megapixels. For image viewing, the DEV-3 and DEV-5 have dual 11mm displays, each of which has a resolution of 852 x 480 pixels, with each pixel comprising separate red, green and blue dots, for a total dot count of 1,226,880 per eye. There's a -3.5 to +3.5 diopter adjustment, 14.3mm eye relief, a 35.6 degree, 16:9 field of view, and an adjustable interpupilary distance of 55 to 75mm.

Two-dimensional video capture is possible at up to 60 frames-per-second with a progressive scan resolution of 1,920 x 1,080 pixels (aka 1080p / Full HD), using MPEG-4 AVC / H.264 (AVCHD 2.0) compression. Standard-definition capture is also possible at unspecified resolution, using MPEG-2 Program Stream compression. 3D video capture uses Sony's proprietary MVC format, with unspecified (but high definition) resolution and frame rate. Movies include stereo Dolby Digital audio.

Data is recorded on Secure Digital cards (including the higher capacity SDHC and SDXC types), or on Memory Stick PRO Duo Mark 2 or PRO-HG Duo cards. Sony recommends use of Class 4 or higher SD cards. Power comes from a proprietary NP-FV70 lithium ion rechargeable battery pack, rated as good for 155 minutes of 2D recording on a charge. Connectivity includes a stereo headphone minijack, high-definition HDMI or component video outputs, standard definition composite video output, USB 2.0 High Speed data, and a DC input.

The Sony DEV-3 and DEV-5 have what the company describes as a "stealth" design which keeps external controls and markings to a minimum, reducing the likelihood of wildlife being scared off by the user's movement. Both models have the exact same size and fairly hefty weight, which weighs some 2.65 pounds.

The Sony DEV-3 is, as you'd expect, the lower-priced model, carrying a tag of some US$1,400 approximately. For the added GPS receiver, bundled accessories, and more powerful digital zoom, the Sony DEV-5 carries a $600 premium, shipping at around US$2,000. Both models are expected to be available in the US market from November 2011.