1. A method for detecting defects on a wafer, comprising: generating output for a wafer by scanning the wafer with first and second inspection systems; generating first image data for the wafer using the output generated using the first inspection system and second image data for the wafer using the output generated using the second inspection system, wherein the first inspection system comprises a first light source configured to generate first light, a first stage configured to move the wafer, and a first detector configured to detect light from the wafer and to generate a first portion of the output, wherein the second inspection system comprises a second light source configured to generate second light, a second stage configured to move the wafer, and a second detector configured to detect light from the wafer and to generate a second portion of the output, wherein the first and second light sources are not the same light source, and wherein the first and second stages are not the same stage; combining the first image data and the second image data corresponding to substantially the same locations on the wafer thereby creating additional image data for the wafer; and detecting defects on the wafer using the additional image data.