Magnification is a standard feature of the mod- ern endoscope and widely used in conjunction with agents that can be sprayed on to the mucosa, such as acetic acid to enhance mucosal detail. Novel techniques that rely on fluo- rescence and narrow band imaging to enhance visual contrast are becoming increasingly used for the identification of muco- sal abnormalities that are not easily seen with white light, e.g. in patients with Barrett’s oesophagus undergoing endoscopic surveillance.