sentences:  A video magnifier however is limited only by its display size and its electronics; video magnifiers that can be switched between 2 and 50 times magnification are common, and displays can range from smartphone-sized to TV-sized.Most video magnifiers can automatically focus the image, and the more advanced models are capable of further electronic image processing to change the colours, enhance the contrast, and/or assist in the tracking of images.Some can be set to save "snapshots" of previously-seen images.