1. An imaging apparatus comprising: first converging means to converge incident light from a subject; transmitting means to transmit the incident light converged by the first converging means to be parallel light; splitting means to transmit, at a predetermined transmittance, the incident light made to be parallel light by the transmitting means, and also split part of the incident light made to be the parallel light to the right and left; second converging means to converge the incident light which has transmitted the splitting means; first imaging means to image a basic image of the subject, by converting the incident light converged by the second converging means into electric signals; third converging means to converge each incident light split by the splitting means; and second imaging means to image disparity detection images having disparity as to each other, by converting each of the incident light converged by the third converging means into electrical signals.