# Adjusting the Display Scale

If the resolution or the contrast on your Preview display is not proper, you can adjust them in "Option -> Setup Parameters -> [Display]".
1. Adjust the Start: parameter of [Display].
Setting H-scale to 4 means a reduction to 1/4 in the horizontal direction. If the dpi (setting in -dpi:) is 360, the resolution in the horizontal direction will be 360/4 = 90 dpi on your preview display. Usually, it would be appropriate to select a value of 70 dpi -- 120 dpi with your display resolution.
The reduction of the resolution in the vertical direction is specified in V-scale .
If you want to reverse the lightness and the darkness on your screen, then check the reverse box.
When the display resolution is reduced, the contrast can be adjusted by using the gray scale.
Note: In practice, when displaying a dvi file, you can adjust the scale in preview display by " Display -> Size -> Magnify, Reduce " (can be set by using the tool bar buttons) and the contrast by "Display -> Contrast -> Blacker, Whiter".
After these, the parameters in Start: of " Option -> Setup Parameters -> [Display]" are now assigned with the current values. To carry out 2. below, it would be better to use these values .
2. Press [Save] to register to Registry (cf. Q_S1).
3. Press [Apply] to apply the settings to the current dviout session.