A method of scanning an object is disclosed comprising the steps of providing a scanning device having a probe and a sample holder whereby the sample holder is rotatable relative to the probe, providing a first feature for indicating the start and/or end of a scan, and recognising the first feature whereby when the first feature is recognised the scanning device is ready to start or end a scan. The scanning device may have a fixed stop which comprises the first feature alternatively, the first feature is provided on the scanning device or on the object. A second feature, located on the scanning device or object for example, may be provided wherein the first feature indicates the start of a scan and the second feature indicates the end of the scan. Also disclosed is an apparatus for scanning an object.