Better Pictures How To: What Makes an Image Blurry
Often students in my classes will bring in images that are blurry or pixelated and ask, “What happened?” Sometimes the answer is easy, other times the photo takes some study to understand why the camera failed to produce a crisp image.
Here are the most common reasons for blurry pictures and how to prevent them:
Too Low Light
If your camera does not have enough light to work with, it will choose a combination of settings that will make the image bright enough at the sacrifice of quality.
The first of these settings is the shutter speed. The shutter is the window that opens and closes to let the light in. If it opens and closes very fast, it can stop action such as someone running. If it is slow, even people standing still will not be “frozen” in time, and just the movement of your finger dipping the camera slightly to push the button will cause blur.
Your camera will give you a “shake warning” with either a hand or a camera with little “shake” marks beside it if it is worried that the shutter is too slow for you to hand hold the camera. If you get a shake warning, try one of these things:
- Place your camera on a table or other surface to take the shot. Use the self timer if you can to avoid any movement when you push the button.
- If you must hold the camera, brace your elbows on a table, shelf, sofa, or any surface for extra stability.
- If you must stand freely, pull your elbows against your body, hold the camera up to your face (look through the view finder the old fashioned way), hold your breath, and push the button as gently as possible.
The second of the low light settings that can make a picture blurry is the ISO “film” speed. If the camera senses low light, it will pick a “faster” film speed, which results in odd colors, bits of colored pixels, and a blurred appearance. If your camera is resorting to this (and you can see the dancing colored pixels discoloring the scene), your only option is to find a way to get more light on the scene. Make sure your flash is turned on if you can use it, but realize you may have simply maxed out the capability of your camera.
Using the Wrong Setting
Sometimes a blurry picture is simply a matter of telling the camera you are photographing something that is moving.
When you place your camera in straight automatic mode, it has no idea what you are shooting–a tree or a track star. It will assess the light and the distance that you are focusing on, and pick a middle range of settings.
If you TELL the camera your subject is moving, it will choose a faster shutter speed. The action setting on your camera is usually found by pushing the “menu” or “set” button and finding the icon of a running man or, if you use a Canon, “kids and pets.”
If, however, you are shooting action such as a volleyball or basketball game indoors, you simply may not have the capability to freeze the action of the game. Pros use extremely large lenses to capture enough light in those very difficult shooting environments.
Too Much Zoom
When you maximize the zoom on your camera, two things may happen:
- A little wobble at the back of the camera where you are holding it becomes a BIG wobble at the end of that lens sticking out. This can create motion blur even when you don’t have a shake warning. Hold the camera very steady or zoom back a little.
- Your camera may go into a “digital zoom” mode. This is a terrible setting that CROPS your picture. Your 7 megapixel image is now only maybe 4. And then it does something WORSE. To make you think it is still a 7 megapixel image, it does something called “interpolation,” which digitally generates fake pixels so that the file size is the same. This crop and interpolation ruins your picture, giving it jagged edges and random dots of strange color. Look it up in your manual and figure out how to turn it off.
Need more help? You can read other Better Picture How To features on the blog. Deanna also has many classes (including the new mom and child photo fun day) as well as private lessons.
