Consider a 2cm long slider used to set zoom values in the range from 0.1 to 10 (i.e. from 10% to 1000%). Using ZoomSliderScale, the first centimeter of the slider will correspond to zoom values from 10% to 100%, and the second centimeter will correspond to zoom values from 100% to 1000. On the other hand if a simple linear slider were used, all zoom values between 10 and 100% would have been squeezed into the first two millimeters of the slider, making it very hard to set those values.