| Exposure controls are very important to | | | | In a digital SLR camera, light isn't always being |
| understand. You may wonder what exposure is. | | | | projected into the lens. In fact, the camera is only |
| Exposure is simply the amount of photons that | | | | exposed to photons for a short period of time. |
| the sensor in the camera detects as it takes the | | | | Usually, the amount of time a camera's sensor |
| picture. In order for a good exposure in a picture, | | | | (similar to our eye's retina) is exposed to light is |
| the correct amounts of photons are required. If | | | | measured in fractions of a second. If you would |
| too many photons are captured, it is called being | | | | like however, this interval of time can be changed. |
| overexposed. Too few photons captured won't | | | | The shutter of a camera is what determines |
| register hardly anything. | | | | when the light of your photograph is allowed into |
| If there is a lot of light bouncing around in the | | | | the camera. Another name for the shutter of a |
| area that you are trying to shoot, then you can | | | | camera is the gatekeeper. Many times, the |
| imagine the sensor in the camera to be illuminated | | | | shutter is mechanical and it responds directly to |
| in a very short period of time. If there is less light, | | | | the users input. |
| then it will take longer for the photons to get to | | | | It is possible for certain digital SLR cameras to |
| the sensor. Always remember that there is a goal | | | | have both mechanical and electric shutter |
| amount of exposure for each shot. That ideal | | | | systems. That way, exposures can range from 1 |
| shot only allows that precise amount of photons | | | | 180th of a second, to 1/8,000h of a second. This |
| to be captured into the lens of your DSLR | | | | is a massive range and the electronic shutters are |
| Camera. | | | | great because mechanical shutters can only take |
| DSLR Cameras are equipped with a digital SLR | | | | exposures 1/500th in length. |
| exposure system which is put in place to improve | | | | It is important to take from this that long shutter |
| your chances of taking a shot with that ideal | | | | speeds allow more light in than shorter ones. This |
| amount of light. The SLR exposure system | | | | is a great benefit for dark subjects. Short shutter |
| adjusts the length of time the sensor is allowed | | | | speeds however limit the amount of blurring that |
| to take in photons. You can manually make these | | | | may occur. The shorter the amount of exposure, |
| adjustments by changing your camera's shutter | | | | the less time there is for the subject to move or |
| speed and lens opening controls. | | | | for the camera to move. |
| Your Exposure Time Machine | | | | |