The Sony DSC-T90 is based around a 1/2.3" SuperHAD CCD image sensor with 12.1 megapixel resolution coupled to a Carl Zeiss Vario-Tessar branded 4x optical zoom lens. The Sony T90 offers equivalent focal lengths that range from a 35mm wide angle to a 140mm telephoto, while the maximum aperture varies from f/3.5 to f/4.6 across the zoom range. Macro focusing is possible down to a minimum of one centimeter in what Sony dubs "magnifying glass" mode.. The T90 forgoes any optical viewfinder in favor of a 3.0" touch-panel wide-aspect LCD display with 230,000 dot resolution.
The Sony Cybershot T90 offers ISO sensitivity ranging from 80 to 3,200 equivalent and includes both true mechanical image stabilization, as well as Digital Image Stabilization which functions by raising the camera's sensitivity (and along with it, the noise levels) so as to achieve a higher shutter speed and reduce motion blurring.
The Sony T90 also offers face detection capable of differentiating between children and adults, recognizing and prioritizing one specific individual's face whenever they're present in a scene and detecting when your subject blinks during an exposure. The T90 takes into account the locations of detected faces when calculating autoexposure and autofocus variables. There's even a dedicated "Smile Shutter" button which triggers the T90 to capture a photo upon detecting that the subject is smiling.
The Sony Cyber-shot T90 features in-camera retouching capabilities, with soft focus, fish eye effect, cross filter, partial color, retro, radiation, red-eye correction, trimming, unsharp masking and smile effects on offer.