There are basically only two category’s of photo blur and the difference is in your control
Creative Photo Blurring
Unwanted Blurriness in Your Photos
Creative Blur – This is the Blur that makes your photos stand out. It is usually a result of understanding how blurring is affected by movement, f-stops, and speed settings. A little knowledge is the key to opening the door to your creativity and insuring the WOW factor for your photo creations. This photo illustrates the power of using blur and focus to guide your viewers eye.
Unwanted Blur – This is any blur that detracts from your photo. It is usually a result of not understanding why the blur is occurring and how blurring is affected by movement, f stops, and speed settings. A little knowledge is the simple fix for this group of blurring problems.
So regardless, if you want to control blur or eliminate blur the information in this tutorial will be of value. The difference between being happy or disappointed with your photos depends more on your basic knowledge of how your camera settings work then what your camera costs.
Learning to use a shallow depth of field and or being purposeful with long exposures, means you will be able to control the blur in your photos and achieve the creative blur that makes your photos stand out. Here are some examples of what can be accomplished with the information in this tutorial.
- A sharp and intentional focal point (photo)
- Streaked Lighting Effects Using Long Exposure
- Silky smooth effects for water and other moving subjects (photo)
Lets look at the technical elements of blurry photos?
Any movement of your camera or your subject will cause blur. The bigger the movement and the longer the exposure the more blur. The best way to avoid blurring caused by camera movement is to use a tripod or stabilize your camera.
- Camera movement will cause the entire photo to be blurry. This is seldom a desired effect unless you are creating a background to be composited with another photo. If your camera is completely still on a tripod and the subject of your focal point is still than your subject will be in focus, even when using a long exposure.
- A Moving subject will blur even if your camera is on a tripod. The longer the exposure the more blur you will get. This is because the longer your aperture is open the more the subject will travel across the frame causing a smear effect on the sensor as it is exposed. This technique of using longer aperture speeds is often used as a creative tool to create soft dreamy water in a landscape scene.
Depth of Field (DOF) Definition
DOF is determined by how long your lens is, how close you are to your subject, and the size of your aperture. A large aperture (1.4) used with a long lens (200mm) is often used to create background blurring(Bokeh) in portrait photography.
Focus (optics) Definition
This is simply camera focus achieved from focusing your lens. Choosing your focal point is critical to directing the eye of the viewer to the most important part of your image. In portraits the focal point is usually the subjects eyes.
How do I create a sharp Image in my Photos with a Blurry Background?
- Choose a Long Lens or shoot close to your subject.
The longer your lens, the more background blur you can get! A longer lens allows you to get further away from your subject and zoom in, which will create greater amounts of blur. I can get amazing background blur with my 16-35mm 2.8 at close range, See Lens or my 70-200mm, 2.8 for farther away. See Lens
- Choose a Wide Open F-Stop
A wide f-stop like 1.4, 2.8 or as wide as your lens will go. The wider your f-stop is, the smaller the depth of field will be. A way to remember this is to remember that if you squint, your eyes are more focused. In the same way the smaller your F stop the more in focus your image will be. F stops are fractions so smaller numbers mean bigger openings. 1.4 is a large aperture opening F22 is a very small opening.
- Position Your Subject Away from the Background
The further your subject is from the background, the more blur you will get. If your subject is right up against the background, it will be much harder to not have the background in focus. So, separate your subject from the background as much as you possibly can.
How do I create a sharp scene with silky water flowing through it?
The key to capturing a photo with the silky water caused by blurring is two fold.
- Eliminate all movement of your camera by using a sturdy Tripod and even a remote to trigger your camera. Here are some links to examples of a low cost remote if you do not have one.Nikon Canon
- Use a long exposure setting that will allow you to properly expose the image. You have two options to make this work.
- Shoot in very low light such as just past sunset.
- Use a ND filter to block out the Daylight. Usually a ND 10 stop filter is what you will need for daytime shots.
Here are the steps to shooting a long exposure shot
- Set up your camera on a Tripod or in a way that it will not move at all during the exposure time. Remember that any small vibration can cause unwanted blurring. This includes small movements from pressing your shutter release button so this is where you might want to use a remote shutter release.
- Compose your image. If you are using an ND 10 stop filter you will have a hard time seeing through them and so will your camera so you will need to set up your shot composition and focus points before putting the ND filter on your lens. This will ensure that your composition is what you want and your focus won’t accidentally “hunt” on you.
- Set the correct exposure. Do not shoot in aperture priority mode because a strong ND filter will often fool a camera’s light meter. The first step to finding the correct exposure is to set your f stop to the desired f-number and take note of the shutter speed that gives you the correct exposure. Put the ND filter on your lens and get ready to do a little math. If you do not like math and want to skip this step you can get an app to do the math for you such as this one.
Doing the Math
- For each stop you darken your shot with a filter you will need to increase the light with your shutter speed setting. So if you add a 10 stop ND filter (decreasing your light by 10) you will need to increase your shutter speed by 10 stops. (Allow the light to come in 10 times longer. ) Since one stop means doubling your exposure time you will need to double your exposure time 10 times. Do do this the long way on a calculator is to press 2x2x2x2x2x2x2x2x2x2 = 1024 The short way is to press 2^10 = 1024.
- Now multiply 1024 x the original shutter speed number and you will have the correct shutter speed when using the ND 10 filter. For example an original shutter of 1’ x 1024 = 1024 so set your new shutter speed to 1000. (closest rounded off)
- Lets do the same math with a ND filter of 6.
- 2^6 = 64 (remember 2x2x2x2x2x2)
- Original shutter is 125
- 64 x 125 = 8000 (your new shutter speed setting)
Quick tip – another form of simple math is counting. Most cameras are set so that 3 clicks equal a stop. So if you want to increase your stops by 10 stops multiply it by 3 and then click your shutter speed 30 clicks to increase it 10 times. Again 3 clicks for each stop you want to go up.
- Take the Picture