An improved optical imaging system includes a vertically stacked pixel array and a lenslet array for capturing images while minimizing the focal length. The vertically stacked pixel array is configured to operate as an image sensor. The lenslet array is configure to focus the image on the image sensor. Each lens of the lenslet array focuses an image on a sub-array of the image sensor. Each sub-array is shifted from one another so that additional data obtained for each equivalent pixel in each sub-array. An image is obtained by combining the data of each sub-array.