Paul Timpa Photography Blog Photography Tutorials and Tips from Paul Timpa Photography

27Mar/09Off

How To Take Sharp Pictures / Avoid Blurry Photos

Brooklyn Bridge, New York City

Brooklyn Bridge, New York City

Taking sharp photos is one of the most important “technical” aspects of photography, as sharpness plays an important role in the quality of your image. Having your photo tack-sharp can often be the difference between a simple snapshot and a professional-looking image. This guide will provide pointers for ensuring your photos are pin-sharp.

(As a side-note, there will be many times when you’ll intentionally want to blur the background or have areas of your photo out-of-focus. That’s an artistic decision. This guide’s goal is to discuss sharpness in the areas where you want it.)

Probably the single most common cause of blurry pictures is camera movement during the exposure. Even the slightest movement of the camera during an exposure will result in some blur and loss of sharpness. So how can we fix this?

One of the most important ways to ensure sharp photos is to use a fast shutter speed (short duration). The longer the shutter is open, the more chance for the camera to move and the more any movement will be picked up. Once you start to get above 1/1000th of a second, blurry shots due to camera movement becomes almost a non-issue. So how short is short enough for the shutter speed? There used to be a “guideline” that said when handholding a camera, the shutter speed should be at least 1 over the focal length – meaning, if you’re shooting with a 100mm lens, the shutter speed should be at least 1/100th of a second. Shooting at 200mm, the shutter speed should be 1/200th of a second, and so on. (This of course refers to shots that are handheld – shots from a tripod do not need to follow this rule). This guideline needs to be updated though, as it is no longer accurate. I recommend doubling the focal length and using that as your guideline. For a 100mm lens, I’d shoot at a minimum of 1/200th second. For 200mm, I’d shoot at least 1/400th a second, and so on. (For a technical explanation of why we need to double the old rule, you can reference my other post “ The Camera Crop Factor”.) Just following this simple guideline will greatly increase your number of “keepers”. So how do you get the shutter speed that fast? There are a few ways.

The most common (and arguably best) way to ensure your shutter speeds are fast enough is to use a wide aperture for the shot. The wider the aperture (smaller the number), the more light gets into the camera. The more light, the faster the shutter speed. That’s why lenses with wide apertures such as F2.8 or F1.4 are known as “fast lenses”. It’s because they allow a fast shutter speed. That’s also why fast lenses are generally needed for low-light and night photography – their wide apertures allow enough light to get in, even in the dark, for you to keep shutter speeds at reasonable levels. Provided that having an out-of-focus background is acceptable (wide apertures create a blurred out-of-focus background when shooting up-close), shooting at F5.6 and wider will help ensure fast shutter speeds.

The second way to increase shutter speed is to adjust the ISO. If you’ve already reached the widest acceptable setting for your aperture and there is still not enough light to achieve the shutter speed you need, you’ll have to increase the ISO. Increasing the ISO by one level (one “stop”) doubles the shutter speed. For example, if your ISO is set to 100, and the meter shows the shutter speed for the scene at 1/30th of a second (too slow to handhold), increasing the ISO to 200 (which is one stop) will double the shutter speed to 1/60th of a second. Increasing the ISO one level again, will double the shutter speed to 1/120th of a second. You may ask, “well why wouldn’t you just always shoot at high ISOs to ensure sharp photos?” The answer is because high ISOs degrade picture quality. The lower the ISO, the better the picture quality. High ISOs lead to noisy photos (little speckles of colored or white dots) and a loss of sharpness. I personally try to shoot on ISO 100 as much as I can. I will occasionally use ISO 200. ISO 400 and above I use only for shots that simply can’t be taken any other way. You may often see in magazines and advertisements references to great “high ISO performance” – they’re referring to the ability of the camera to keep noise levels down, even at high ISOs. The better the picture quality at high ISOs, the more versatile the camera. The Canon 5D Mark II for instance, goes up to ISO 6400 allowing fast shutter speeds in very dark conditions.

Another option which enables fast shutter speeds, and one we’re all familiar with, is adding light. For most of us, this basically just means using the flash! By using the flash, you are adding enough to light to use fast shutter speeds, which is why you almost always use flash in dark conditions like indoors or at night. Keep in mind this only works on subjects within the range of the flash. I generally find that anything farther than twenty feet away is too far. Flash will not help with city skylines, sports, night landscapes, etc. It will however, help with night shots of people, food, close objects, and photos taken indoors. Set your camera to 1/200th of a second using shutter-priority mode, turn on the flash, and you will almost always get sharp photos of close objects at night. A shutter speed of 1/200th may result in a dark background. If you want the background to be brighter, you can try lowering the shutter speed, but then you have to be careful about your subject moving, and ensuring that any ambient light from the room, street lights, etc. doesn’t light up your subject (in addition to your flash), or you will see two versions of the person you are photographing – one from the flash, and one from the room lights (this is commonly known as ghosting).

After shutter speed, focus is probably the next most common source of unsharp photos. Most cameras have excellent autofocus systems, but it’s important to know how to use them. Here are a few tips:

If your subject is not moving, I recommend using a single focus point in the center, and using that to focus. Multiple focus points are especially useful for moving objects, but I find it much better and easier to use just the center point, especially on stationary objects – otherwise, you can’t be sure what the camera is going to focus on. For instance, if you are taking a photo of a person in front of a mountain, and you have multiple focus points, it’s certainly possible the camera may choose the focus point that is on the mountain, resulting in a pin-sharp mountain but a very blurry photo of the person. If the subject is not in the center of the frame, simply move the camera so the focus point is on the subject, press the shutter half-way, and recompose the shot and take the picture.

In addition to using auto-focus, you should also get familiar with using manual focus. Manual focus is necessary in a variety of situations. In low-light, indoor, and night photography, auto-focus systems often have trouble finding focus, because it’s too dark. This is often a good time to focus manually. Alternatively (and this is the technique I use most often at night), move the camera so that you can use the camera’s center focus point to auto-focus on your subject. Press the shutter half-way to try to focus -- it may take a couple of tries to lock focus. Once you’ve successfully locked focus, then switch the lens to manual focus and recompose the shot. This way, when you click the shutter to actually take the picture, the camera is not searching in the dark for the focus point. You’ll have successfully used auto-focus to determine the focus, but then by turning it off, you’re preventing the camera from getting confused when you go to take the shot.

After shutter speed and focus, the next most common reason for unsharp photos is related to the aperture you select, and how it affects picture quality. There are two main ways aperture directly affects picture quality. Firstly, due to the way lenses are designed, they are often not their sharpest at their widest aperture (smallest number). Provided there is enough light to reach the shutter speed you need, it is generally worthwhile to stop down a few stops from maximum. I generally try to use at least F5.6 whenever I can. Many people feel that the sharpest aperture is generally around F8, and up to F11. It’s also important to note that small apertures (high numbers) also degrade quality (I’ll discuss that more below). The “sweet spot” is usually known to be between F8 and F11, but for me, I’m comfortable with F5.6 to F13. The second point related to aperture is depth of field. At wide apertures, depth of field (meaning the area that is intentionally kept in focus vs. the area that is intentionally blurry) is very small. At wide apertures, the area that is in focus could be just a few millimeters, with everything behind or in front of the focus point being blurry. For example, let’s say you have a 200m lens and you take an up-close photo of a friend at F2.8. If you focus on the person’s nose, only the nose will be in focus. The eyes and the rest of the face will be blurry, as well as anything in front of the face. In this case, you’ll want to stop down to F8 or above to keep everything in focus. It’s a common belief that since small apertures increase depth of field, it’s always best to use a small aperture to keep everything sharp. The problem with this is that small apertures decrease the overall sharpness of the whole picture due to something called “diffraction”. Even though the entire scene will “technically” be “in-focus”, you will actually have lost sharpness throughout the entire picture by using a tiny aperture. Unless you need the shutter speed to be very slow (to blur water in a waterfall for example) avoid using the smallest apertures like F22 or F32.

Of course, using a tripod or otherwise stabilizing the camera is always a great option. I won’t get into too much detail as I’m sure many of you are familiar with tripods or just resting the camera on a bench, railing, or anything handy. I’ll make two points though. Firstly, when using a tripod or other support, always use the camera’s self-timer or a remote control to fire the shutter. Your finger pressing the shutter button will cause enough shake to make the photo blurry. If your camera has a “mirror lockup” feature, you can also use this. You may know that when you click the shutter, the mirror flips out of the way so that the light can hit the sensor. The flipping of this mirror can cause the camera to shake, which is especially visible when using long lenses. By setting the mirror lockup, you are flipping up the mirror before the actual picture is taken, preventing camera shake and the resulting blur.

By using these tips, you should be able to get sharp photos in a variety of situations. Keep the shutter speeds fast, the aperture in the sweet spot, and the focus in the right area, and you’ll be shooting pin-sharp photos every time.

I've also created an app for iPhone, Android, and iPod Touch which teaches you photography -- more info can be found here:

Photography Trainer for iPhone and Android

Photography Trainer iPhone app

Photography Trainer iPhone app

If you have any questions or comments, please let me know.

Best,
Paul

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