Digital cameras are now more than 30 years old. They benefit from an exceptional popularity that the conventional film cameras never obtained. Digital cameras differ from conventional analog cameras with respect to several distinctive features, some of which stand as undeniable improvements, some remaining on the contrary as brakes towards their use in every technical field. However, in the last years, these distinctive features are fostering new techniques of world observation, these techniques relying merely on the openings proposed by the new sensors. Here is the domain of Computational Photography. Before we present a critical survey of the objectives of computational photography, a review of the distinctive features of digital cameras is made, in order to determine where progress may be expected.