Macro lenses are used in applications when the object size is approximately the same as the size of the camera sensor (between 10x smaller to 10x larger).  They are very low distortion and offer superior depth of focus than general purpose lenses but not as much as telecentric lenses.  Most macro lenses have a fixed working distance and often have no moving parts making them ideal for industrial applications where unwanted adjustments could cause problems although there are also zoom models available.Linescan macro lenses have very large image circles and thus can be used with large format area scan or typically linescan cameras with lengths up to 62mm.High resolution, versions give superior optical performance to standard resolution models allowing resolving power to 5 microns.These lenses are generally optimised for use in the visible spectrum but some models are also IR corrected.