An optical scanning apparatus, a system and a method of optical scanning independently determine illumination spot size and spacing. The apparatus includes an array of optical emitters to provide a plurality of optical beams and a plurality of microlenses to receive the optical beams. The microlenses form an intermediate image of the array at substantially unity array magnification. The apparatus further includes an adjustable collimator to receive the plurality of optical beams from the intermediate image, a beam scanner to scan the optical beams in an in-scan direction, and a scan lens to focus the scanned optical beams. An arrangement of illumination spots forms an image of the array.