Why are pictures of computer screen weird?

As more things happen digitally, there’s a growing need to be able to capture what’s happening on a screen as a picture. If you want to share a funny Facebook post to Instagram, or a Tweet with a WhatsApp group, sending an image is often the simplest way to do it.

It’s also really useful, when you’re looking for help online, to be able to show a picture of any errors shown. Obviously, taking screenshots is an important skill for all Envato Tuts+ writers.

In this tutorial, I'll show you why taking a photo of a screen doesn’t work, and how you should capture pictures of what’s on the screen of a Mac or iOS device.

Digital cameras don’t work anything like the human eye; screens are completely different to pieces of paper. Although this might seem obvious in theory, it’s at the root of why cameras and screens don’t play nicely together.

When you look at something, the brain is doing a huge amount of processing. It'll make up information to fill in any gaps.

A Hollywood film is just a stream of 24 still images per second played one after the other, but our brain interprets it as a scene that’s in constant movement. No matter how hard you try, you’ll never be able to see it as individual images.

Both screens and digital camera sensors are made up of a pixel grid. My MacBook’s screen has 5,184,000 pixels arranged into 1,800 rows and 2,880 columns. My camera, on the other hand, has 22,118,400 pixels in a 5,760 by 3840 grid.

When you look at the screen or take a picture with the camera, it might look like you’re seeing an image with curves and circles, but it’s actually just tiny squares arranged to look that way.

The strange pattern you see in digital images of screens is what happens when two grids interact. Unless the grids line up perfectly, you get some weird optical effects called moiré.

When you take a picture of a screen, the camera’s grid won’t be able to accurately represent the screen’s grid unless they’re aligned exactly. The camera has to make decisions about how bright and what colour each pixel is, and the algorithms it uses to do that start to fall apart when they’re applied to grids that are prone to moiré patters.

The camera is actually making these judgements with every image you take, it’s just that the effects aren’t as obvious as they are with screens.

A screenshot is an image of a screen’s contents. It’s taken by the device and saved as a file. On a Mac, it’s simple to take a screenshot. All the screenshots you take are saved to your Desktop.

To take a screenshot of the Mac’s full screen, press Command-Shift-3. A PNG file with the same resolution as your screen will displayed on the desktop.

If you don’t want to take a full screenshot, press Command-Shift-4. The cursor will turn into a crosshair that you can use to Click-and-Drag an outline around the area you wish to capture.

To take a screenshot of a single application window or menu, press Command-Shift-4 and then the spacebar. Click on the window you wish to capture and it’ll be saved to the desktop.

Normally, when you take a screenshot you’re interested in capturing the content on the screen, not the Mac’s UI. This means that macOS doesn’t save the cursor in the image files. If you want to take a screenshot that includes the cursor, you’ll need to use a different method.

Open Preview and go to File > Take Screenshot > From Entire Screen. A timer will start so position the cursor where you want it and wait until it runs out.

Rather than being saved to the Desktop, the screenshot will open up in a new Preview window. Save it to whatever location you wish.

To change where screenshots are saved by default, open the Terminal and paste in the following command and press Return:

defaults write com.apple.screencapture location ~/Documents/

Afterwards, enter killall SystemUIServer and press Return again.

Now, all the screenshots you capture will be saved to the Documents folder. You can change the folder path to wherever you want.

Taking screenshots on an iOS device is even easier. Press the Home and Lock buttons at the same time and you’ll hear a camera shutter sound.

Any screenshots you take on iOS devices are saved to the Camera Roll. If you open the Albums tab in the Photos app, you also find them in a dedicated Screenshots album.

A digital screen is refreshed multiple times per second. Our eyes don't catch this process (because the brain smooths it out to make the screen look consistent), but cameras do. That's why any picture of a computer screen looks very different from the real thing.

Above are just a few of the distortion problems faced by users. There are several poor monitor display issues, reported in different forums.

Flashing, stretched, pixelated, weird color lines and other distortions don’t let you work. Especially, if you are a designer or professional, you cannot work with such a display screen.

Addressing the problem, here we bring methods that you can try to fix distorted, flashing, or skewed images on your monitor or laptop.

A distorted monitor or laptop does not always require a professional’s intervention. There are simple DIY troubleshooting methods you can try.

Try the below methods to fix laptop or desktop monitor flashing or distortion issues:

Distorted images on laptop or desktop monitor can occur if the cables are damaged, broken, burnt, or loose. So, begin by checking the cables and connections of your computer.

Ensure all the cables including the video or VGA cable are plugged in to the device properly. Chords should not be bent, lose, or defected.

Restart after updates or software installation re-initializes the drivers and hardware parts. Restart can fix many logical and physical problems including faulty display of monitor.

With continuous usage over the time, the screen settings may get changed. Reset the monitor to its default settings. Press the menu or settings button on the desktop or LCD monitor. This opens the main menu. Now, select ‘Restore Factory Settings’ option.

The menu setting options vary with brand and model. For instance, Dell monitors usually have ‘Factory Reset’ while Samsung monitors show ‘Reset all’ option.

Note: If you don’t find any reset option, turn off your monitor by pushing the ‘Power’ button. Next, disconnect the monitor from the computer. This should reset the monitor settings to default.

Degaussing refers to eliminating a magnetic field. Electromagnetic buildup can sometimes distort the display picture. This is common with older CRT (Cathode Ray Tube) monitors.  If you are using CRT monitors, try degaussing to fix the distorted display problem.

Degauss method may vary with monitors as below:

Degaussing is only limited to CRT and not required in LCD and Plasma monitors.

Sometimes external devices connected or near your computer build up electromagnetic field that leads to overlapping, scrambled or distorted screen.

Try to fix display screen by keeping away any speakers, mobiles, or other electronic devices from your computer.

If you are facing widescreen monitor, stretched, pixelated or blurry display on monitor or laptop, adjust the screen resolution.

Note: The path to screen resolution option may differ depending on the manufacturer and model of your desktop or laptop.

Steps to fix distorted image in Toshiba laptop

You can visit the manufacturer’s website and check your computer’s manual for right resolution of your CRT, LCD, or laptop. Typically, the below resolutions are recommended for respective screen sizes:

Update your computer driver, if above methods don’t fix distorted image on monitor.

Steps to update the device driver:

You can also download the drivers directly from the manufacturer’s site. Make a note of the make and model of your desktop monitor. Visit the support page of the manufacturer’s website and follow their instructions.

If updating graphic cards don’t help, reinstall them. Reinstalling fixes most of the video cards related problems such as distorted image, overlapping, or corrupt display screen.

Steps to uninstall the driver follow the below steps:

After uninstalling graphic drivers, reboot your computer. Windows will automatically reinstall the drivers.

Faulty graphics card can also cause distorted, flashing, or skewed display on monitor. Replace video card and check if it fixes distorted display problem.

If your computer is very old, you may have to replace the complete motherboard. This is because the old computers used AGP technology, which may not be found today. Modern graphics cards run on the PCIe interface.

This is the last resort. When all the above methods fail, including replacing your video card, then change the computer monitor.

Here we suggest to first test with a different monitor. If the problem is resolved, opt for a new monitor.

If the screen problem continues, it’s a hardware issue that needs repair by a professional. Contact the manufacturer or the authorized service center of your computer or monitor.

This could be a file corruption issue. Photos would appear grainy, blurry, greyed-out, pixelated or distorted on screen, when they are corrupt.

Use a photo repair software — Stellar Repair for Photo to fix such corrupt images.

Download the software on your computer, and follow the 3-step process –

You can repair multiple photos of any format simultaneously. The software can fix corrupt and distorted JPEG, JPG, DNG, HEIC, TIFF, CR2, CR3, NRW, SR2 and many other image file types.

It’s recommended to use the software’s free trial. Preview the repaired image to be assured if the distortion gets resolved.

Distorted image display can hamper your work. Begin troubleshooting by checking the cable and other connections. Then move on to other given methods in order of their mention. Replacement of video card, motherboard or monitor should be last on your list.

Hope this post was helpful. Do share with our readers how you were able to fix distorted, flashing, or skewed image on your monitor or laptop.