Digital Camera Shutter
Most important - The Digital Camera Shutter!
The most important button on any camera is the one that releases the digital camera shutter, which opens to let light inside when you capture an image. It can be a bit disconcerting, but if you look straight into the lens and press the button, you will see the digital camera shutter open and close. What happens when the digital camera shutter opens, is that light travels across the face of the sensor. If it closes quickly, less light will enter. If it closely slowly, more light will enter. It's as simple as that.
So when we describe shutter speed, we say how quickly (or slowly) it will open and close, for example 1/100th of a second or 1/150th of a second.
The amount of light that reaches the sensor directly affects exposure, as do lens aperture and the sensitivity setting you use. The only problem is that unless you have manual controls, you won't be able to set exposure or aperture, both of which are inter-related. However, you should be able to set light sensitivity, which is shown as an ISO number. You can leave this on auto, or use your navigation buttons to select one of the various options. Remember that the higher the ISO number, the more sensitive to light the camera becomes.
Here are some examples:
• Use ISO 100 for taking photographs outdoors in bright sunlight.
• Use ISO 400 for indoor photographs or those taken in low light.
• Use ISO 800 or 1000 for moving objects or low light situations where you don't use a flash.
The aperture is an adjustable opening in a diaphragm in the lens through which the light passes to reach the shutter and then the sensor. We describe its size with F-numbers (or F-stops) and if we can manually change the F-stop, we increase the size of the aperture by using smaller F-stop numbers. Because the aperture controls the light, it not only affects exposure, but depth of field as well.
Happily, you should have an EV compensation facility that will allow you to adjust exposure by one or two F-stops, depending on the model and how sophisticated it is. Basically what this does is to allow you to adjust the amount of light that enters the lens when you capture the photograph or image. So you can then lighten or darken the image when the brightness between the subject and the background isn't balanced.
In addition, the release mechanism of automatic units should have two pressures: a half press that activates the focus system and measures available light, and a full press that actually fires the mechanism and captures the image. By using the half press, you can increase control, because you allow the system to focus for you.
Other functions will also help you to balance light and improve focus, white balance, depth of field and so on, even if you can't manually control your digital camera shutter.