There are several main reasons why a digital photograph might lack sharpness. First of all, let’s make a distinction between “blurry” and “grainy.” Just to keep things simple, I will use those two terms for now. Let’s start with “grainy” and get it out of the way. Graininess, or more properly, digital noise is introduced when a high ISO is used. When taking photos, you want to use the lowest ISO possible, as a general rule. I will reveal why this is in a later essay because it is somewhat complex (where I will cover ISO at length), but for now just remember that higher ISO = more digital noise. Another source of “graininess” is when a lower resolution (quality) is chosen. There is a setting on practically every digital camera where you can make a selection between varying quality of images. You might wonder why a person would choose a lower quality at all. The reason for this is that the lower the quality, the more pictures you can hold on your memory card or subsequently your hard drive. So it’s a trade-off: you get more pictures for your buck, but then you sacrifice quality. The reason for this is that for higher quality photos, there are more pixels per inch – meaning that the individual pixels are actually physically bigger. Each pixel is a little different colored square or block that makes up a part of a complete picture. It’s basically a mosaic.
Now let’s talk about blurry. There are three main reasons for a picture being blurry: 1) movement, 2) camera is out of focus or 3) obstruction somewhere between your subject and the camera’s sensor.
Movement (or motion)
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| Motion blur shows movement |
Motion might be from your subject or your camera – or both – at the moment the shutter is open. Motion blur is sometimes desirable (when used correctly and appropriately) because it demonstrates a more natural appearance of motion, as opposed to an object or person being “frozen” in action. Other than that, motion blur is usually not preferred. There are a couple of ways to prevent unwanted motion blur: 1) You can take measures to keep your camera and subject from moving. This can be accomplished by practicing better shooting techniques (learning to depress the shutter release button without moving the camera) and/or by using a tripod or some other means to steady the camera. 2) Increase the shutter speed of the camera, which may require you to increase ISO and open your aperture – which increase the chances of noise and blur if not used correctly. I have already mentioned the use of higher ISO, but not wider aperture. A wider aperture (lower f-stop number) decreases the depth of focus, so in such instances if your area of focus is off just a little bit, some essential parts of your subject will be blurry (out of focus).
Out of Focus
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This is a perfect example of a photo lacking composition and
focus. Nice picture of the couch!
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One thing that I find quite often with amateur photographers is that they just can’t wait to press the shutter button… even if the shot isn’t composed or if the camera isn’t focused or ready. Instead of getting a half-dozen good photographs, you end up with a hundred snapshots. I have overheard amateurs discussing the “advantage” of digital photography is that you can shoot a whole bunch of shots and you get a few that turn out looking nice. This shotgun approach to photography rarely gives satisfying results (from my perspective anyway). One of my friends who is friends with a professional photographer told me that the pro ALWAYS comes away with professional looking photos. The reason why is that he knows how to set up the shot BEFORE fully depressing the shutter release button. It may only take a fraction of a second (for a seasoned photographer) but ensuring that the lens has focused on what it is supposed to focus on, the lighting is properly compensated for and that the shot is composed makes the difference between a professional photograph and a blurry snapshot. On most DSLR cameras, there is an indicator that tells whether the lens is focused or not. Some lenses take awhile to autofocus. In some cases, it may be necessary to override the autofocus and manually focus. One rule of thumb when photographing people or animals is that to ensure the eyes are in focus – tack sharp. Other features are much more forgiving. This is especially important when using a wider aperture.
Obstructions
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Leaf or branch obstructing view of frog, causing
undesirable blur
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I’ll give a broad, general term to the word obstructions because basically it is any foreign matter that doesn’t belong in-between the subject or the sensor. It could be dust, smudges or scratches on the lens or maybe your finger or camera strap is in the way. You may be trying to shoot through a dirty window or window screen. It could also be tall grass or branches that are in the way. One thing also to consider is that your camera’s sensor will eventually get dust on it. My recommendation is to get it professionally cleaned. Don’t ever use sprays, solvents or compressed air. You could ruin your camera. Sometimes, even though obstructions are not necessarily visible, they will have a profound affect on the sharpness of your photograph.
So there you have it, in a nutshell. It gets a lot more complicated, but if you know where the problems lie, then you can go into greater depth to try to solve those problems and work toward being a better photographer. Simply being aware and taking a little bit of time and mental awareness in this matter will IMMEDIATELY give you dramatic improvement in your photography skills.
