What are the causes of blurry photos? — “Why my pictures are blurry?” You might have asked this question to yourself atleast once. Or your friends might have asked you this question when they show you the photos they have taken. Blurry images are a nightmare to anyone who takes photographs. You cannot fix it in any photo editing software. There’s nothing you can do about it unless you know the causes of blurry photos.
Most people may not realize that their images are blurred until they transfer it to a computer. When they review the images in their camera’s LCD, everything seems fine. This happens due to the low resolution of the LCD behind your camera (But if you zoom in the images, you can spot the blurriness) Eventually they end up blaming the camera. Well, your camera is innocent here. The blurry images are due to certain technical errors and shooting situations. Once you know the causes of blurry photos, you can fix it very easily.
There are two main types of blur – motion blur/blur due to subject movement, and blur due to camera shake(Camera shake is the movement of camera during an exposure). There are multiple causes for blurry photos. Let me explain each one of them for you.
The 7 causes of blurry photos
1.Motion blur/blur due to subject movement
This often happens in low light due to the slow shutter speed. If your subject is moving and the shutter speed you have selected/or the camera has selected does not freeze the movement, the resulting photograph would appear blurred. This is usually observed when you use your camera in automatic mode in low light. When the camera switches to automatic mode (night mode), it selects a slow shutter speed to let in more light. Eventually, the images will become blurred due to either subject movement or camera shake. You can notice this effect as a double exposure.
2.Improper holding of camera
A firm grip would help avoiding camera shake. Always hold your camera properly while taking a photograph. Make yourself and the camera as steady as possible while pressing the shutter release button. Tapping or snapping the shutter release button is another cause for camera shake. Tapping the shutter release button results in a slight movement of the camera during the exposure causing blurriness. Instead of snapping it, simply press the shutter release button to avoid camera shake.
3.Focal length of the lens
Longer focal length makes the camera ‘unstable’. When you use a longer focal length (100mm, 200mm, 300mm etc.) you will notice slight shake in your view finder. If you are using a compact/point and shoot camera , you will notice a slight shake in your LCD when you zoom in. But when you use small focal length (zoom out in some cameras), there won’t be any shake in the viewfinder.
4.Shake due to internal vibrations
This happens after you press the shutter release button. When you press the button, a vibration passes along the lens which causes a slight movement in the camera.
5. Depth of field
Depth of field is the area of focus in the picture/it is the near to far sharpness in the photograph. A shallow depth of field has a very small area in focus and the other areas are blurred. The shallow depth of field happens when you use a wide aperture, when you are too close to the subject/magnification of the subject is high, and when you use a long focal length. It will be difficult to get the image in focus when you use a shallow depth of field. This is one of the reasons why your images appear blurry when you take photos using ‘night mode’ in your camera (‘In night mode’ the camera selects the widest aperture to let more light in). However, using a narrow aperture also causes blur due to ‘diffraction effect’. If you use large f-numbers(above f16) in a cropped sensor, then fine details in your images are blurred ( I shall write more on this in my future posts)
6. Dirty lens
If you have a dirty lens, your photographs would be blurred. Mist, greasy smears, smudges in front of your lens give you blurry photos.
Focusing on a wrong area in your image results in a blur. Blurred images are produced when you focus on an area and move your camera for recomposing the shot. This mostly happens in point and shoot camera where the preferred focus point is at the center. Other reasons are movement of you or the subject during focus.