An apparatus for performing low coherence ranging of a sample with high transverse resolution and large depth of focus, comprising an optical ranging system comprising a light source, a means for directing light from the light source to the sample, a means for directing reflected light from the sample to a detector, at least one detector, a means for processing light data received by the detector and which generates an image and an optical element having a transverse resolution defined as DELTAris less than or equal to about 5microm, and a depth of focus DELTAz of at least about 50 microm.