Once you start photography there are many things that become clear. The first is that lighting is essential to creating a good image. The second thing is that the digital medium has made things much faster and easier. Thirdly, we realise that camera usage is crucial to getting good photos. Once these three things come together we can begin to feel satisfied with our images.
Once we understand that different subjects and different scenes require different settings, we can then proceed to take beautiful images. Shutter speed and aperture are the two biggest things we must concern ourselves when aiming for sharp images. Shutter speed is responsible for the amount of time that the shutter is open. Aperture is responsible for depth of field and light coming into the sensor.
Once you start exploring shutter speed you will soon realise that there’s more to it than letting light in. If you are shooting at night, for example, and you choose a shutter speed that is too fast, then you will find your images will be very underexposed. The shutter simply closes to quickly to let any decent amount of light in. On the other hand, if you choose a shutter speed that is too slow, you may run the risk of over exposing your image. Sometimes, when our shutter speed is too slow we can create blurry motion. Blurring the motion is good for special effects, but not good when you want tack sharp images.
Shutter speed is one of the main factors to image sharpness. An accidental blurry image is often due to hand holding the camera when the shutter speed is slow. It is very difficult to take a photo with a slow shutter speed and get absolute sharpness. You can have the best intentions in the world yet still managed to blur the photo just by standing there.
So what is the slowest shutter speed you can use when handholding the camera? In my personal experience it lives somewhere between 1/80th and 1/ 50th of a second. I can quite confidently shoot at 1/80th of a second can see no blur. Some people can shoot at 1/50th of a second and see no blur. You may be different. Your neighbour or friend may be different to you and me. This does not make it right or wrong. It simply means there is a limit that we have as individuals to how low we can go.
A helpful way to improve the sharpness in your images, without a tripod, is to set your shutter speed at the same number as your focal length. If you are shooting with a 50 mm lens then try not to shoot slower than 1/ 50th of a second. If you are shooting with a 200 mm lens then try not to shoot less than 1/200th of a second.
The further away your subject is the longer the focal length you will need. The longer the focal length you will need a faster shutter speed is required. This is because the more you zoom the more the image shakes and moves in the frame. You will have to compensate for this by choosing a faster shutter speed. One very tiny movement can completely blur your image. This happens simply from breathing or just standing.
If you are shooting with an SLR you’ll be able to see what focal length you have by looking down the barrel of your lens. Around your lens is a series of numbers. If you have a 24 to 105 mm lens you will see a series of numbers ranging from 24 right through to 105. As you zoom further into your subject you will see a small indicator next to the number. For example if you see this small indicator next to the number 85 then you know that you are shooting at 85 mm.
Matching the shutter speed and focal length number is a good way to improve image sharpness. However there is a limit to this. You cannot apply this rule to very slow shutter speeds unless you use a tripod. For example if you are shooting a landscape at 20 mm then I can guarantee that setting your shutter speed to 20th of a second will not improve your sharpness. You need to be realistic about how slow you can go with your shutter speed before you need the help of your tripod.
The matching your shutter speed to your focal length to attain sharpness may not be visible straight away. You won’t be able to see a massive improvement when you look at the image on the lcd screen on the camera. When you get your photo onto the computer is when you will see the difference. Once you zoom into your photo you will see differences in sharpness. Once you see the sharpness is maintained throughout the image you will not need to over sharpen your images in post production.