The present invention concerns an imaging apparatus which works for size reductions, power savings, the efficient attainment of the quantity of light sensed, and prevention of contrast decreases due to a
diffraction phenomenon, is well fit for the taking and appreciation of common still pictures, and comprises a taking lens and
electronic imaging device combination that takes full
advantage of the characteristics of an imaging device. The imaging apparatus comprises a taking optical
system, and an
electronic imaging device which is located on an image side of said taking optical
system, includes an imaging plane I with a plurality of two-dimensionally arranged light sensors, and is adapted to convert an image formed through said imaging optical
system into electrical signals. In at least one taking state, the apparatus satisfies at the same
time condition (1) about relations of the area of the
entrance pupil to the
focal length of the taking optical system, condition (2) about the number of effective pixels of the imaging plane, condition (3) about the effective area of the imaging plane, and condition (4) about the division of the effective area of the imaging plane by the number of effective pixels.