Projector Calibration Test Screen

Press Go full screen to project a focus grid, then step through an edge frame, dark patches and focus lines.

Pattern Pick one, then go full screen.

What to look for

F goes full screen. Escape leaves.

Focus grid, 32 by 18 squares

Focus grid, 32 by 18 squares

Preview · scaled to fit

A black and white grid for a 16:9 projector: on 1920 by 1080 every square is 60 pixels, on 1280 by 720 it is 40. Focus on the middle squares, then look at the corners. Edges that lean show keystone.

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1 of 6

Click, tap or press the right arrow for the next one. The left arrow goes back.

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What to look for

Shape: keystone, stretch and spill

Focus across the picture

Room light and the screen surface

Next step Lines soft everywhere? Check the signal's real pixelsNext: a plain white field for uneven patches

All 20 patterns and readings

Patterns the page draws 6

  • Dark patches for a lit room, levels 8 to 80 Ten gray patches on black, at levels 8, 16, 24 and on up to 80 of 255. In a dark room all ten should show. With the lights on or daylight in the room, the lowest ones sink into the screen's own gray.
  • Edge frame with lines 1, 2 and 4 percent in A white line on the very edge of the picture and three more inside it, 1, 2 and 4 percent in, with a cross in the middle. It shows how much of the picture lands past the border of the screen.
  • Focus grid, 20 by 15 squares The grid for a 4:3 projector. On 800 by 600 every square is 40 pixels, and on 1024 by 768 a little over 51. The squares are larger than on the wide grids, which suits a small or distant picture.
  • Focus grid, 32 by 18 squares A black and white grid for a 16:9 projector: on 1920 by 1080 every square is 60 pixels, on 1280 by 720 it is 40. Focus on the middle squares, then look at the corners. Edges that lean show keystone.
  • Focus grid, 32 by 20 squares The same grid for a 16:10 projector. On 1280 by 800 every square is 40 pixels and on 1920 by 1200 it is 60. On a projector of another shape these squares come out wider or taller than they should.
  • Focus lines on black, 1, 2 and 3 pixels White lines one, two and three pixels wide on a black field. Turn the focus ring until the one-pixel lines are as thin as they get in the middle, then see whether they stay that thin toward the edges.
Show all 20 patterns and readings (14 more)

Shape: keystone, stretch and spill 7

  • A 4:3 projector showing a 16:9 picture A 1024 by 768 projector fits a 16:9 picture into 1024 by 576 and leaves a dark band of 96 rows above and below. The bands are part of the panel, so the 4:3 grid still fills the whole lit area.
  • A 16:10 projector showing a 16:9 picture A 1280 by 800 projector shows a 16:9 picture as 1280 by 720 with a band of 40 rows above and below. On 1920 by 1200 the picture is 1920 by 1080 and each band is 60 rows.
  • Keystone correction costs pixels Correction reshapes the picture inside the projector so that it lands as a rectangle. Fewer of the projector's own pixels are then used, which lowers the resolution. On the focus lines the thinnest ones turn uneven.
  • The left or right edge stands taller The projector stands to one side of the screen's center line, so one side of the picture is farther from the lens and comes out taller. Moving the projector left or right until both sides match is the usual cure.
  • The outer line falls off the screen When the edge line is missing on one side, the picture is larger than the screen surface there. Count which inner line is the first to land on the screen: 1, 2 or 4 percent of the picture is spilling past.
  • Picture wider at the top than the bottom That is keystone. A projector on a table looks up at the screen, so the top of the picture travels farther and spreads wider. The grid's outer columns lean outward. A projector square to the screen shows no lean.
  • Squares that are not square If the grid for your projector's shape shows cells wider or taller than square, the picture is being stretched: the signal from the computer has one shape and the projector is filling another. Try the grid for another shape.

Focus across the picture 2

  • Middle sharp, top or bottom soft A lens focuses at one distance. When the projector is tilted, the top and bottom of the screen are at different distances, and the lens can only be set for the average. Squares blur toward one edge.
  • One corner softer than the other three The same cause in two directions at once: the projector is both tilted and off to one side, so one corner of the screen is farthest from the lens. Check each corner square of the grid against the middle.

Room light and the screen surface 5

  • A bright patch that moves when you move That is a hot spot, a blurred reflection of the projector's lens in a glossy screen surface. On such a screen it shifts as you change seats. A matte white surface scatters the light more evenly.
  • A larger picture looks more washed out The same projector light spread over a larger picture leaves each part dimmer, so room light takes away more of the contrast. A smaller picture from the same projector is brighter, so the same room light takes less of it.
  • Black squares that look gray in a dark room Light from the white squares bounces off the walls and ceiling and back onto the screen, where it lifts the black squares. A real room always returns some of it, so black next to white is never as dark as an all-black picture.
  • Dark patches lost to room light Room light falls on the whole screen and lifts black to gray, so patches darker than that gray disappear. Note the lowest level you can read with the room as you will use it, then again with the lights off.
  • No brightness figure on this page A web page cannot measure light, so nothing here gives lumens or a brightness reading for a projector. The patterns only show what your eye can tell apart on your screen, in your room.

How this list was compiled: Written for this page. Every square size and band height was computed: a square is the picture's width divided by the number of columns, and a 16:9 picture on a wider or taller panel is the panel's width times 9 over 16. That projecting onto an angled surface makes the picture a trapezoid, larger at the top for a projector on a table looking up, that some areas may then be out of focus because the lens is set to the average distance only, that moving the projector left or right corrects a sideways error, and that keystone correction reduces the number of pixels used and lowers the resolution, are from https://en.wikipedia.org/wiki/Keystone_effect. That real rooms reflect light back onto the picture and lower its contrast, and that a checkerboard is the usual pattern for measuring contrast within one picture, are from https://en.wikipedia.org/wiki/Contrast_ratio. That a glossy, high-gain screen shows a hot spot whose place depends on where the viewer sits, and that contrast in a projected picture depends on the light in the room and the size of the picture, are from https://en.wikipedia.org/wiki/Projection_screen. The projector resolutions 800 by 600, 1024 by 768, 1280 by 720, 1920 by 1080, 1280 by 800 and 1920 by 1200 are from https://en.wikipedia.org/wiki/Video_projector. All read 2026-10-02. Nothing on this page measures light. Licence: own work

How it works

This projector calibration test screen fills the picture with a black and white focus grid in one press. Five more patterns follow: grids for 16:10 and 4:3, an edge frame, dark patches for a lit room and focus lines.

Read the full guide

Set the picture up in this order

1. Press Go full screen on the grid that matches your projector's shape. 2. Square the picture: columns that lean mean keystone, so move the projector before using its correction. 3. Focus on the middle squares, then check the corners. 4. Next steps on to the other grids, the edge frame, the dark patches and the focus lines.

Projector test screen 4:3, 16:10 and 16:9

Each grid has square cells on one shape only: 32 by 18 for 16:9, 32 by 20 for 16:10, 20 by 15 for 4:3. Cells that are not square mean the picture is stretched.

  • Run the dark patches twice, lights on and lights off: the difference is what the room costs you.

Questions and answers

Can I save a screen resolution test image for a projector?

Yes. Save as PNG saves the pattern on show as a picture made in your browser, at the size of the screen this page is on. Open that file on whatever plays to the projector.

Why is the projected picture wider at the top?

The projector is below the screen's center and tilted up, so the top of the picture travels farther and spreads. That is the keystone effect. Raising the projector removes it; keystone correction hides it and uses fewer pixels.

Does this page test projector brightness?

No. A web page cannot measure light, so it gives no lumens and no brightness reading. The dark patches show only which near-black levels you can still see in your room.

Why are the corners blurry when the middle is sharp?

A lens focuses at one distance. If the projector is tilted or off to one side, the corners are nearer or farther than the middle, and the lens can only be set for the average.

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