Electron diffraction patterns showed the expected honeycomb lattice. Transmission electron microscopes are often used in electron diffraction mode. These surface textures can be visualized using electron backscatter diffraction (EBSD) or related diffraction techniques. Optics is the study of light motions including reflection, refraction, diffraction, and interference. Various spectroscopic techniques also require samples to be mounted on substrates such as powder diffraction. Voigt profiles are common in many branches of spectroscopy and diffraction. The study of polychromatics is particularly useful in the production of diffraction gratings. It is similar to what occurs when waves are scattered from a diffraction grating. This is evidenced by the absence of Bragg peaks in X-ray and neutron diffraction. The resulting wave interference pattern is the basis of diffraction analysis. Grains from which electrons are scattered into these diffraction spots appear brighter. Transmembrane helices are visible in structures of membrane proteins determined by X-ray diffraction. They are amorphous, showing only weak diffraction. The use of computational methods for the powder X-ray diffraction data analysis is now generalized. It was one of the first crystal structures to be obtained using X-ray diffraction.