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Adjusting Your Monitor
For Optimum Viewing

a horned owl

The Owlcroft Company

The Owlcroft Company maintains numerous sites intended to give you information and pleasure. But you won't get the full intended value of our sites--or of anyone's sites--if your monitor is not adjusted optimally. Colors that look pleasing and text that is easy to read when seen on a properly adjusted monitor may look strange or be hard to see properly on a monitor whose adjustments are off. And all too often, folk with ill-adjusted monitors are not aware of the problem (it's not as if flesh tones look green or something).

We have thus set up this little page to help anyone who is unsure whether their monitor's settings are fully optimized. It's a piece of cake to do, and once done right rarely needs touching up for a very long time. So just take a few minutes and follow these simple steps to more pleasing viewing.


Too many computer users take their new monitor out of the carton, plug it into the main box, and do nothing more. That is a shame, because few monitors are in exact adjustment right out of the box, and not fine-tuning your monitor can leave you--all unknowingly--having a less than optimum viewing experience. If you find yourself asking how this or that web-page designer could have used those colors, maybe it's your monitor that's off (or maybe those designers really are idiots--you won't know until you check your monitor).

There are two major classes of adjustments you can make: those that affect the size, shape, and position of the screen image, and those that affect the content of that image. (It is most likely a defect in the second class that has brought you to this page.)

Before beginning, the most important thing you need to know is how to adjust your monitor's controls. The first step, if it's possible, is to carefully read the manual for the monitor (I say "if it's possible" because many users won't have that manual around any more). Most modern monitors are controlled electronically using pushbuttons usually located somewhere along the bottom of the front of the monitor; older monitors, of which many are still in use, have physical knobs or dials along the bottom edge of the monitor front face.

If you don't have your manual any more, simply inspect the face of your monitor closely; as a rule, what you need to know can be deduced from what you see. Indeed, on many monitors the labels are tiny pictures, to avoid language barriers.

Not every monitor will have every one of the controls I describe. If you are sure that your monitor is not equipped with a control I mention, just pass over that adjustment. (But most monitors will have most or all of these controls.)

From here out, I necessarily assume that you at least can locate and operate the various controls I will be referring to. Don't worry about how to use those controls--that's what this page is all about--just be sure you know where they are.

Another point: don't try any of these adjustments until your monitor has been on for at least an hour: monitors do "warm up" and look different after such warming-up times.

Also, we need to understand this very important bit of terminology: the difference between the screen and the illuminated screen image. The screen is the physical glass-covered area visible within the plastic (or metal or whatever) frame around it; it is the very dark grey glass you perceive when the monitor is switched off. The illuminated screen image is the lit-up part of the screen you see when the monitor is in use; it is what the monitor projects onto (so to speak) the screen proper. The illuminated screen image may exactly match the screen proper in size (which is the ideal), or it may be smaller (in which case there will be a small unilluminated black band around it), or it may be larger (in which case the outer edge of the true screen image is invisible to you, clipped off as it were). Try to get used to looking at the screen image, probably defined by the edges of your on-screen "desktop," as a single entity, regardless of what's actually on-screen; think of it as "the lit up part."

Note: With most or all of these controls, there are two ways to go about the adjusting, and which will work better depends on the particular person making the adjustment. One method is the "incremental": you make tiny incremental changes until you get the result you want. That method is the most obvious and works for most people. Sometimes, though, especially if the wanted result is a judgment call, what works is to run the adjustment up and down, from way off in one way to way off in another way (with optimum somewhere in the middle) several times, eventually trying to stop in the middle, at the optimum. Try both methods for any given adjustment and see which you prefer.

Settings Affecting Screen Content

The basic controls here are familiar from television sets (on which they are usually far more horridly maladjusted than on computer monitors): brightness and contrast. There is also, on some monitors, a simple "color intensity" adjustment, while others have much more complex color-control settings; of the latter sort of control, I will say little here; but brightness and contrast alone are often so maladjusted--without the user's being aware of the problem--that screen content is needlessly contaminated, often badly.

Brightness and Contrast

These two controls interact. Moreover, they don't adjust what you might think from their names (the "contrast" really adjusts the brightness and the "brightness" really adjusts the base "black" level).

There are many web pages dedicated to helping you adjust your monitor, and I link a few below. But not all explain well what to do in what order--they just say "adjust the controls until the image looks right," or words to that effect. Be aware that the commonest error in monitor setting is having the (mis-named) "brightness" up too high.

For a beginning, do this:

  1. Turn the "contrast" control (usually marked with a circle divided vertically, one half filled in) up all the way.
  2. Turn the "brightness" control (usually marked with a little sun-like image) all the waydown--but finish reading these instructions first! (On a few monitors, turning the brightness down all the way may completely blacken the screen.)
  3. Slowly turn the brightness up until you can just discern clearly each of thedifferently-shaded boxes in the black-to-white strip below; pay especial attention at the left (dark) end. When you can just discern, without straining, the leftmost box and the one just right of it, stop. Be sure to initially run the control past that point a bit, then run it down and up a few times; you want to get this one right. You may be tempted to set the control higher than what I have described; if you do, true black will be faintly gray and, worse, subtle differences in some colors will be hard or impossible to discern.

Black-to-White Tone Strip

  1. Try backing the "contrast" control off a little, keeping an eye on the image below. If the picture seems to improve with a little reduction of "contrast" from maximum, leave it set there. Note that the white areas ought to merge seamlessly with the background of this page. Be sure you can clearly discern every step on every color strip.

Color and B/W Monitor-Calibration Chart


Of color adjustments I will say only a little, having little expertise in the more advanced aspects of the matter.

If your monitor is old or primitive enough that it has a simple "color" (or "color intensity") control, back that off all the way (everything will become black-and-white), then advance it until the colors look about right, preferably on a picture containing lots of natural color--a landscape with people in the mid-foreground would work well. "Color," when such a control is present (as it is on most television sets) is usually set far too high, giving--among other things--bleeding or saturated reds.

If your monitor also has a "hue" control (as, again, most television sets do), adjust it by using the old standby of getting human flesh tones to look right.

If, as many modern monitors do, yours has a "color temperature" setting, you can try cycling through however many preset combinations it has to see which looks best. (On my monitor, there are four such settings, and each changes the color of "pure white" significantly.) I would not try to play with the actual detailed settings unless you know very well what you're doing (at least write down the original values before fiddling).

More Information

Here are a few links to external monitor-adjustment pages (I suggest you visit them all).

  • Browser Adjustments (from help4web): includes monitor settings, but also some other things you ought to look at if you never fiddled with your browser's defaults.
  • (more to come soon)

And here are some links to more general pages about monitors and viewing them.

Settings Affecting Screen Layout

Before proceeding with these adjustments, a preliminary setup is wanted. Find the vertical and horizontal screen size controls. Using them, shrink the screen-image so that there is a clear border of unilluminated black screen around the illuminated image--say a half inch to an inch (the exact size is not important--what is important is that you be able to clearly distinguish the illuminated image from the total screen area). Now proceed.


"De-Gaussing" is not actually a control: it is a one-time operation. It is, crudely speaking, an electronic form of brushing off cobwebs from the monitor's picture tube. The chances are, for a given monitor, that it will not improve the picture, but it might, and it can't hurt (done correctly--more in a moment). If it does help, it will do so by slightly sharpening the focus--pictures will look less fuzzy (if they were a little fuzzy).

The primary thing to know about degaussing is that you don't do it for long or often. When you do it, if the control is a physical button, do not hold it down, just press and release it. And whatever, do not repeat degaussing any more often than once an hour. (Once done, it should not need re-doing for at least many months; just don't be tempted to repeat it if it does make an improvement.) Keep in mind that most monitors automatically do a degaussing every time they are turned on: if you turn your monitor off frequently (many do not), you needn't worry about trying degaussing.

Locate the monitors's "degauss" button or control, and actuate it. Remember: if it's a physical button, do not hold it down, just press and at once release it. The screen image will at first go all wobbly, but--within a very few seconds--will again stabilize.

And that's all there is to that.


Examine the illuminated screen image carefully to see that all four edges are perfectly straight lines. Don't worry at this point if those lines are not exactly parallel to the screen area or at perfect right angles at the corners: just be sure that all four are straight. If you are satisfied that all four are perfectly straight lines, move on to the next adjustment. If they're not, or even if you're not quite positive, stay here.

If the four edges are not perfectly straight, obviously they will be curved. You will find that such curvature will be consistent: if any one edge "bows" in, all four will; if one "bows" out, that's what all four will do. (If the edges are noticeably bowed, the illuminated image will somewhat resemble an old-fashioned pincushion, hence the name of the adjustment that controls such edge-bowing.)

The adjustment is simple: play with the "pincushion" control until all four edges are perfectly straight lines. And that's all there is to that. (But you may have to close one eye and align the other with the edges to be sure of straightness.)


Not every monitor will have these adjustments. If you are sure yours does not, just go on to the next adjustment.

"Geometry" encompasses two forms of adjustment: "trapezoidal" and "keystone." (Some monitors may have one but not the other; trapezoid adjustment is more common.) Trapezoid adjustment is used to assure that the sides of the illuminated screen image are at perfect right angles to the base; keystone adjustment is used to assure that the top edge and the bottom edge are exactly the same length.

That said, using the controls is obvious. Start with trapezoid adjustment. Tune the control until one of the bottom corners (you can inspect either) is, in your judgment, a perfect right angle. Be aware that the entire illuminated screen image might, at this point, be slightly tipped with respect to the monitor screen face; if so, ignore that. Just make that bottom corner a true right angle, even if that angle is tipped with respect to the monitor face.

Then, for the keystone adjustment (if available), tune the control until one of the top corners (again, either will do) is a perfect right angle. (The same comments about screen tipping apply here as for the trapezoid). And that's that.

Screen Rotation

(This adjustment might instead be labelled "Tilt.")

You should by now have made the illuminated screen area a perfect rectangle. Inspect that rectangle to determine whether it is perfectly parallel to the actual physical edges of the screen, or, if you prefer, to the entire monitor face. If it is, or might be, a little tilted with respect to those physical edges, use the "screen rotation" (or "tilt") control to align it perfectly. And that's that.

Screen Position

There will be two controls under this heading: vertical and horizontal. You should now have, as a result of your tuning so far, an illuminated screen image that is a perfect rectangle perfectly parallel to the overall screen area but a little smaller than that area. Use the vertical screen position control to center that rectangle vertically, and--of course--the horizontal screen position control to center that rectangle horizontally.

Do not be concerned yet with perfect accuracy--just get the image approximately centered up for the moment: you will be coming back and tuning the centering further after the next adjustment. Indeed, this and the next adjustment work together--you will do one then the other and back again and again until the image is fully set.

Screen Size

This also has two forms of adjustment: vertical and horizontal. You used these controls before, in setting up for adjustment, to shrink the screen image down a bit. Now that that image is (or should be ) in all other ways geometrically perfect, use these controls again to expand the screen image to just fill the physical screen proper.

Do the adjusting slowly. You may well find that, as an example, the left illuminated screen area reaches the left edge of the physical screen before the right edges correspond; in that case, you need to go back and tweak the horizontal location control. And, of course, the same applies to vertical adjustment.

Start with one dimension, horizontal or vertical--which doesn't matter. Expand the illuminated screen image until one edge just meets the corresponding physical screen edge; then go back and tweak the location until the illuminated image is again centered (roughly halve the gap at the edge that did not meet); then expand the image a little more; and so on. The idea is to end up with both edges of the illuminated screen image each just meeting the corresponding edges of the physical screen simultaneously as you adjust the size.

Repeat the process in the other dimension. And now you're done with screen-layout adjustments.


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