The shutter is almost like an internal organ inside of your camera. When isn’t working right your camera is essentially useless, so it is easy to get freaked out when that happens. The shutter is one of the absolute vital parts of any photographic camera. From your most basic point & shoot to a multi-million dollar camera used for scientific research, there is some kind of shutter. An easy way to think about the shutter is that it is the last mechanism in the camera before the image you intend to catch reaches the recording medium (the image sensor in digital cameras or the film in film cameras).
Basically shutter is a device that has the ability to be opened and closed; ideally in a consistent uniform manner with the ability to vary the amount of time it is open. The first shutter was basically just a lens cap and a pocket watch. Today shutters vary in size and shape from camera to camera and manufacturer to manufacturer. Their essential purpose is the same though; they keep light from being captured until you want them to for however long you want them to. Of course, when most people talk about a shutter they are most likely thinking about the modern shutter in a DSLR camera (pictured at the top and demonstrated at the bottom). The technical term for this kind of shutter is “focal plane shutter”. The shutter is constructed of very thin black blades. The blades have to be made of a light material so that they can achieve shutter speeds of 1/4000 seconds or higher; that’s 0.00025 seconds if you are not a fan of fractions. If the shutter were too heavy the camera would not be able to open and close as quickly.
Being that it is made up of thin light materials, it is extremely important to keep foreign objects away from the shutter blades. They are very fragile and crack quite easily. Moreover, if the debris happens to get between the shutter blades and the imaging sensor they will be dragged across quickly and violently. When that occurs there is a high potential that the object will severely damage the sensor. A broken shutter is fairly common and not terribly expensive to fix. A sensor, on the other hand, is much more costly in parts and the labor is highly intensive.
Like all mechanical things, your shutter will wear out over time if you are using it so it isn’t necessarily a foreign object or something you did wrong. A number of camera models even have “rating” of how many times the shutter should “click” (shutter actuations/cycles) before it wears out. That number will vary from camera to camera and is not available on a lot of cameras. The best thing to do, if you are curious, is to contact your manufacturer to find out that information and how to go about getting the info off of the camera. If you suspect that your shutter is not functioning correctly or there might be debris in the blades, STOP SHOOTING! It is pretty easy for camera repair technicians to determine the amount of damage suffered so take it in and have it looked at immediately.
HOW THE MECHANISM WORKS…
