Dual screen cameras are sometimes known as dual display cameras. These devices are commonly digital cameras that rely on microprocessor technology in order to receive and process digital images. Such cameras often feature liquid crystal display (LCD) screens that show real-time digital images of what is captured by the lens and chip. The unique characteristic of these types of cameras is that they possess rear-facing and front-facing screens, sometimes featuring a touchscreen menu interface for added function. Having two screens assists the photographer in aligning and configuring shots from either direction and allows subjects to see exactly when the shutter will blink and capture the moment.
Another advantage given by dual screen cameras is the added ease in photographing oneself. With the assistance of a tripod, or perhaps positioning the camera on a platform or shelf, it's possible to aim a camera from the front and compose a self-portrait within the frame. The extra screen eliminates the age-old problem when playing both photographer and subject — of stepping behind the camera and having to imagine one's height and lighting on an imaginary person — and then racing into position. By referring to a camera' s front-facing screen, the photographer/subject can instantaneously evaluate positioning, lighting, and focus for better results. This also aids couples or friends who may want to take a picture of themselves by holding the camera at arm's length.
On many digital cameras, a charge-coupled device (CCD) chip receives light and translates it into electronic information that gets digitally processed. These signals are then transmitted to the screens. This allows photographers to see exactly what images are being recorded, and with what specifications such as zoom or focus, before taking photos. Photos themselves can be taken by either manually snapping shutter releases or allowing timers to activate automatically. Some dual screen cameras also feature automatic subject recognition to assist in automatic focusing, and adjusting shutter speed, aperture, and flash.
Technological innovations permit dual screen cameras to enhance photography in other ways. Some front-facing screens display indicators such as flashing icons to let people know when the photograph is about to be taken. Other screens feature touch-sensitive, or haptic, feedback; this might permit a screen to vibrate to indicate where the finger has pushed a menu button. Automatic subject recognition can sometimes take a shot at the precise moment a subject smiles. This permits an automated but more human touch in a shot than merely using a shutter timer.
Many cameras equipped this way reduce the anxiety of the unknown — that impending moment of shooting — and make their users and subjects more comfortable and prepared. Better informed subjects may make for better photographs. By illuminating not only what's in the frame, but also camera settings like flash, users in front of cameras can know what to expect — especially in light of numerous automatic adjustments. In addition, simple countdown timers ticking on dual screen cameras send subjects clear cues for capturing moments of their own.