By: Infocus Photography & Video | July 10, 2018

How many photos have you deleted because they're blurry? Thank goodness for digital, right? Remember the days of film where you'd only get one shot and if it was blurry, too bad, you didn't discover until sometimes weeks later?


There are different types of blur in photos, and you need to know what's causing it to know how to fix it.

Motion blur

Motion blur happens when something moves - either the camera or the subject. If everything in your photo is blurry, both the subject and the background, then it's probably the camera (or more accurately, the person holding it) that moved. If it's just the subject that's blurry and the background or other people in the photo are sharp, then the person who is blurry must have moved as you were taking the shot.


We'll explain in another blog post how cameras work and the relationship between shutter speed, aperture and ISO, but for this you just need to know that your camera will take a photo at a particular shutter speed and that relates to how long the shutter is open when it is taking the picture. The longer the shutter is open, the more the camera sees. So if you're moving during a shot, the camera will see it.


Here's a quick experiment to explain. Close your eyes, then blink them open and closed again once, as quickly as you can. You'll just get a quick impression of what's in front of you, but you likely won't see anything move. Even if there is a person walking in front of you, you won't see any actual movement, only a still image. But then, open your eyes for a bit longer, up to one second. Notice you'll see movement.


A camera works very much like your eyes. So if you're using a slow shutter speed (and the shutter is open for a longer period of time), the camera will see movement which translates to blur.


At a recent wedding we experimented with long shutter speeds to simulate motion. While these images didn't exactly turn out as intended, they do demonstrate the effect of a slow shutter speed.

 
0.3 at f/22, ISO100
 
1/200 at f/2.8, ISO100

A faster shutter speed will eliminate the camera's ability to see movement, whether that movement comes from the camera or the subject. Without getting too technical, in a bright daylight situation try at least about 1/200th of a second to start with and go from there. If your camera doesn't allow you to manually adjust your shutter speed, try to add some light to the situation (open the curtains, turn on a light, go outside or use a flash). Your camera will see that the scene is brighter and will adjust the shutter to a faster speed itself.

Out of focus

Have you ever taken a photo of two people standing next to each other and found that the tree behind is perfectly in focus but the people are blurry? We call this kind of blur "soft", because it looks like a soft focus.


See the two examples below. The photo on the left is focused on the street in the background (probably because the person on the right threw his head back and laughed unexpectedly, moving him out of the focus point). The photo on the right, taken just a moment later, is focused on him.

 
Out of focus
 
In focus

Your camera has focus points which dictate what part of the image your camera will focus on. If you use a full auto mode, your camera will most likely be selecting which focus point it wants to use for each particular image, which can result in some unsatisfactory results. On beginner model cameras the focus point will often be right in the middle of the image, creating the sharp tree / soft focus people.


To avoid this, you need to move your focus point manually. Each model of camera will have a different looking button for this function, so read your manual if you can't figure out how to do it. Change your focus point while looking through your viewfinder and place it on the part of the image which you want to be in focus. If you're taking a close up shot of a person or an animal, try to focus on their eye.


Another function of your camera which contributes to photos being out of focus is your f-stop, or aperture. Again, we'll explain the relationship between aperture, shutter speed and ISO in another blog post, but all you need to know right now is that the wider your aperture is open (a smaller f-stop number), the less depth of field / more blur you'll have in your photo. If you're photographing two people, one slightly in front of the other, and you're finding that only one is in focus, increase your f-stop number (which means your shutter won't open as wide) and you'll get a greater depth of field and less blur.

Need more help?

Head over to the Ballarat Photographers' Hub Facebook group and join up. As well as being a great online source of information and education, you can also meet new like-minded locals who are interested in photography. We occasionally have in-person meetups so you get the opportunity to chat face to face with other photographers who are always happy to answer your questions.

Category: Hub 

Tags: