How to Fix a Fuzzy Overhead Projector

By Elizabeth Mott

To diagnose overhead-projector focus problems, separate what you're projecting from how you're projecting it.
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Overhead projectors may not enable you to project files and videos straight off your computer hard drive, but they offer a cost-effective way to display printouts of text or visuals prepared in your applications. Once you print your material on inexpensive sheets of transparent plastic, you can use them to present training seminars each time you hire new staff members, or represent your company's offerings at public meetings and client gatherings. To solve out-of-focus problems that lead to fuzzy projections, locate and address the real source of your problem.

Examine your overhead transparencies. If you printed out a low-resolution image, or one that's out of focus to begin with, your output suffers from the same deficiencies as your original. Look for an alternate source for the material, substitute another visual or try to sharpen the original in an image-editing application. If the source offers critical information and can't be improved, verify that your audience can see and understand it.

Look for ripples or creases in your transparencies, flaws in the material that constrain it from laying flat. Replace damaged transparencies with freshly printed copies. When you place your projector film on the platform, smooth out the sheet to get it as flat as possible.

Examine the projection platform for smudges, spots and dust that can interfere with projection quality. Clean the glass according to the device manufacturer's directions.

Adjust the device's focus head to position the projected image as upright as possible on the screen. If the focus head tilts too far, it can cause the image to look stretched, distorting its content. You also may be able to refine the focus by adjusting the position of the mirror within the focus head.

Adjust the focus knob below the focus head on the projection arm. Turn the knob until the image becomes sharp. If you have trouble obtaining good focus, rotate the knob back and forth around the point at which the image becomes sharp, stopping when you see the best projection.

Move the overhead projector closer to the screen. If you position your equipment too far away, you may have trouble attaining a sharp image that's large enough for all members of your audience to see clearly.


Verify that the projector faces the screen squarely. The front edge of the machine should be parallel to the screen.

Keep your fingers off the projector's mirror. Any smudges or dirt on this surface can interfere with image quality.

When you finish your presentation, allow the projector's fan to shut off before you turn off the unit.

If the projector includes a latch to hold its mirror in place, engage the latch before you move the device.


Don't carry an overhead projector by its projection arm. Pick it up by its base.