Methods for using a single electron microscope system for investigating a sample with twin electron beams having different focal lengths include the steps of emitting electrons toward the sample, forming the electrons into a two beams, and then modifying the focal properties of at least one of the two beams such that they have different focal planes. Once the two beams have different focal planes, the first electron beam is focused at the sample, and the second electron beam is focused so that it acts as a TEM beam that is parallel beam when incident on the sample. Emissions resultant from the first electron beam and the TEM beam being incident on the sample can then be detected by a single detector or detector array and used to generate a TEM image.

Methods for using a single electron microscope system for investigating a sample with twin electron beams having different focal lengths include the steps of emitting electrons toward the sample, forming the electrons into a two beams, and then modifying the focal properties of at least one of the two beams such that they have different focal planes. Once the two beams have different focal planes, the first electron beam is focused at the sample, and the second electron beam is focused so that it acts as a TEM beam that is parallel beam when incident on the sample. Emissions resultant from the first electron beam and the TEM beam being incident on the sample can then be detected by a single detector or detector array and used to generate a TEM image.