Photographie and Sound health

Although digital SLRs have fully programmed exposure controls it will enable us to choose both aperture and shutter speed in a fairly sophisticated way. I’ve found that most DSLR users prefer to use aperture or shutter priority exposure modes most of the time because they rather than the camera usually have a better idea of what kind of subject matter is being framed in the viewfinder and therefore what exposure or shutter speed might be best for the scene. For example, if you’re shooting sports, you’ll probably want to use a relatively high shutter speed as often as possible. That speed may be 1/1000th second or 1/500th second or as slow as 1/125th second if the illumination is sparse. But you need to decide the minimum shutter speed you want to use in this kind of situation. Digital SLRs, like other modern digital and film cameras, have a mode called shutter priority in which you set the shutter speed, and the camera uses its metering functions to set an appropriate aperture to create the proper exposure. If not enough light or too much light is present for a correct exposure at the chosen shutter speed, an indicator will appear in the viewfinder, perhaps a readout that says LO or HI, or an LED. You can then manually choose a different shutter speed, but the choice is always in your hands. The reverse is true for aperture priority, in which you set the f-stop and the camera chooses the shutter speed. You might want a small aperture to maximize depth-of-field, or a large aperture to reduce it for a selective focus effect. Again, an alert will appear if the f-stop you prefer is out of the comfortable exposure range. Here is a trick you might not have thought of. You can use the opposite exposure mode than the one you might have chosen in some situations. For example, if you want to use the highest possible shutter speed under changing lighting conditions, instead of working in shutter priority mode, use aperture priority and set your camera to the widest possible f-stop. The camera will automatically choose the fastest shutter speed available to ensure correct exposure. Or, if you want a relatively large or small f-stop for depth-of-field reasons, but don’t mind if it varies by a stop or two either way, select shutter priority and set whichever shutter speed corresponds to roughly the f-stop you prefer. If the light changes a bit in either direction, your camera will compensate by itself.