Why are my photos blurry? Nine causes, and how to fix each one
Blur is never random. Every soft photograph has a cause you can name, and once you can name it, you can usually fix it on the next frame.
You spent twenty minutes by the water waiting for the cormorant to settle. It finally landed on a post close enough to fill the frame, held still, and you fired off forty shots. At home, on the big screen, every one of them is soft. Not wildly blurred. Just not sharp. The feathers look like felt.
A sharp version of that picture, like the one at the top of this page, usually comes down to two decisions: a shutter speed of 1/1000 s or faster, and a single focus point placed on the bird's eye. Neither needs expensive gear.
Blur is never random. It always has a cause, and the cause leaves fingerprints in the image. Learn to read them and you will fix the next shot instead of wondering about the last one.
How to tell what kind of blur you have
Open the photo and zoom to 100 per cent. Then look for these three patterns.
- Everything is soft, with a slight double edge or directional smear. The camera moved. That is camera shake.
- The background is sharp but the subject is smeared. The subject moved.
- Something is sharp, just not the thing you wanted. Focus landed in the wrong place.
If nothing is sharp anywhere and there is no smear, just a general haze, suspect the lens itself. With those patterns in mind, here are nine causes, grouped by where they come from.
Camera settings that cause blurry photos
1. Shutter speed too slow for hand-holding
The most common cause of all. Your hands are never perfectly still, and at slow shutter speeds that movement is recorded. The old guide is the reciprocal rule: use a shutter speed of at least one over the focal length. At 50 mm, 1/50 s. At 200 mm, 1/200 s. On a crop-sensor camera, multiply the focal length by the crop factor first, so 200 mm on a 1.5x body needs about 1/300 s. On high-resolution sensors, go faster still.
Fix: raise the shutter speed, and raise ISO to pay for it. Image stabilisation helps with shake, often by several stops, but it does nothing for a moving subject.
2. Subject movement
Stabilisation and a steady grip cannot freeze a moving subject. A person walking needs roughly 1/250 s. A child running or a dog playing, 1/1000 s. Birds taking off, 1/2000 s or faster. A perched bird looks still, but it shifts, preens and turns its head constantly.
Fix: use shutter priority or manual and set the speed for the movement, not the light.
3. Depth of field too shallow
At f/1.8 and close range, the sharp zone can be a couple of centimetres deep. Focus on a person's nose and their eyes can already be soft. Two people standing side by side, one slightly behind, will not both be sharp.
Fix: close the aperture to f/4 or f/5.6 for portraits of more than one person, and f/8 when you want the whole scene sharp.
4. High ISO noise mistaken for blur
At very high ISO, the camera's noise reduction smooths out grain, and fine detail such as feathers, hair or foliage goes with it. The result looks soft, but it is not blur. It is detail smeared away.
Fix: give the camera more light if you can, and use the lowest ISO the shutter speed allows. If you shoot RAW, you control the noise reduction yourself in editing.
Focus problems
5. The wrong focus point
In automatic area modes, the camera decides what to focus on. It usually picks the nearest or most contrasty thing, which may be the post rather than the bird, or a branch in front of a face.
Fix: switch to a single focus point, or a small zone, and move it onto your subject. For people and animals, the eye. Many recent cameras have eye detection for people, animals and birds; it is worth turning on, and worth checking which eye it chose.
6. The wrong focus mode
Single autofocus (AF-S, called One Shot on Canon) locks focus once and holds it. Perfect for a still subject, useless for one that moves between focusing and firing. Continuous autofocus (AF-C, called AI Servo on Canon) keeps adjusting as long as you hold the button.
Fix: use single for still subjects and continuous for anything moving. If you focus and then recompose at a wide aperture, the plane of focus moves with you; move the focus point instead.
7. Missed focus in low light
Autofocus needs light and contrast. In a dim room or at dusk, the camera may hunt, give up, or confirm focus on something it can see better than your subject.
Fix: focus on a high-contrast edge at the same distance, such as a collar, a window frame or a lit sign. Turn on the AF-assist light if your camera has one. For still subjects on a tripod, switch to manual focus and use live view magnification.
Blur is never random. It always has a cause, and the cause leaves fingerprints in the image.
Equipment problems
8. A dirty lens or filter
A fingerprint or smear on the front element spreads a haze over the whole frame, lowers contrast and creates soft halos around bright lights. Cheap protective filters can do the same.
Fix: clean the lens with a blower, then a microfibre cloth or lens tissue. Try a shot without the filter and compare.
9. Tripod with stabilisation switched on, or a shaky trigger
On a tripod, image stabilisation on some cameras and lenses can hunt for movement that is not there and introduce a faint blur. Some newer systems detect a tripod and adjust automatically, so check the manual for your camera and lens. Pressing the shutter by hand on a long exposure can also jolt the camera.
Fix: turn stabilisation off on a tripod unless your manual says otherwise, and trigger with the two-second timer or a remote release. Hang your bag from the tripod's centre column hook if it has one, and keep the centre column down in wind.
Sharp photos are a habit
Most people find one or two causes account for most of their soft pictures. Once you know yours, the fix becomes automatic. Moving subjects are the hardest test, and a session at our Melbourne Zoo wildlife workshop is a good place to practise focus modes and shutter speeds on animals that do not stay still. If the fundamentals are still new, begin with the beginner photography workshop.
Practise this
- Find your own hand-holding limit. Photograph a detailed still subject at your usual focal length at 1/250, 1/125, 1/60, 1/30 and 1/15 s. At 100 per cent, note where shake appears.
- Photograph a moving subject, such as a friend jogging or a dog, in AF-S and then AF-C. Count how many frames are sharp in each mode.
- Take a portrait at f/1.8 or your widest aperture, then at f/4. Check whether both eyes are sharp in each.
Questions, answered.
Why are my photos blurry when I zoom in?
Why is my camera not focusing on what I want?
What shutter speed stops blur?
Can you fix a blurry photo in editing?
Published by CapturEDU, Melbourne photography education. Our educators are award-winning photographers with a Master of Arts in Photography (RMIT), AIPP and RPS membership.
