A Coddington magnifier provides higher magnification with improved image quality. A magnifier is a device used for magnification. Zoom effects such as the fish eye magnifier and zoom desktop effects provide this functionality. The removable pentaprism could be swapped for a waistlevel viewfinder with a pop up magnifier. The Handy Boy adds a square magnifier which has simple light for illumination. A rival lens is the Coddington magnifier. Even better images can be obtained with a multiple-lens magnifier, such as a Hastings triplet. Magnifier lamps are also task lighting. Microsoft Magnifier, an accessibility utility for low vision users has been dramatically improved. Some high-end slide rules have magnifier cursors that make the markings easier to see. Microsoft's Windows 7 operating system includes a significantly improved version of Magnifier. The drawback is that the diaphragm groove reduces the area seen through the magnifier. In Tesla's more advanced (magnifier) design, a third coil is added. Pressing the Win+Esc combination will exit the magnifier. One of the earliest readers of microfilm was the Coddington Magnifier.