Exposure is an important concept of photography. It is important to understand it to capture good pictures. Without totally understanding the concept of exposure, your picture will not have a perfect result. The image would usually be over or under exposed. An overexposed image will appear to be burnt, forming a white blob of light in parts where the light is excessive. And an underexposed image will be too dark. You would miss the details that you need. Therefore, it is important to understand how to utilize the exposure effectively and efficiently. In this blog, we will understand the concept of exposure and its efficient use with an Auto exposure camera.
Understanding What is Exposure of Image
Exposure refers to controlling the lightness and darkness of the image. In auto exposure cameras, it is controlled by the camera's light meter. It determines the amount of light that should pass the shutter and reach the sensor by adjusting the shutter speed and aperture. Exposure is a combination of f stop i.e. the size of the aperture through which the light would pass, and the shutter speed, which is the amount of times the sensors would be exposed to the light. It means that if the shutter speed is open for a longer period, the amount of light the sensors would be exposed to will be greater, and the image will be brighter. If the shutter is open for very less time, the sensors will not be exposed to much of light, and the image will be darker.
What is F stop
F- Stop is the fraction number of the actual opening of the lens in comparison to the focal length of the lens. The aperture is a conical opening through which light passes and reaches the reflective mirror.
What is ISO
ISO controls the sensitivity of the sensor to light. In bright light, the ISO setting should be low to avoid over exposure, and in low light, it should be increased to increase brightness. With the increase in ISO, there will be an increase in noise and decrease in color. So it is important to set the ISO as low as possible to avoid this effect. But set it too low, and you will end up with a blurry image.
Exposure Compensation
Exposure compensation is an easy way to alter the exposure level when you shoot. It works when you are working with the program, shutter speed priority, or aperture priority modes that are also known as a pro automatic modes. Most cameras will lock the controls for exposure compensation in auto to give you the best exposure in the available light. The camera adjusts its aperture and shutter speed on the lines of the changes you make to compensate for the exposure.
In Aperture Priority mode, you chose the aperture setting that you need, and the camera adjusts the shutter speed to balance the exposure compensation adjustment. Similarly, in Shutter Speed Priority mode, you determine the shutter speed you need. The aperture is adjusted accordingly by the camera. In both these settings, the camera may also change the ISO setting if you have set the ISO settings to Auto.
Exposure compensation is usually used when the main subject you shoot is brighter or darker than the rest of the background. It is usually the case when the light source is in the back of the subject. In this scenario, the camera selects a region from the frame that can compensate the lack of light on the main subject, and brightens the subject accordingly.
We hope this blog helped you understand how exposure works and how you can use auto exposure to compensate and balance out exposure to a great extent. Auto Exposure is a real useful tool to avoid over and under exposure of the the picture. Although we share whatever information we come across in our daily life, it would be interesting to know about your views. Please share your knowledge and views in the comments section.
If you wish to learn more then please enroll for our workshop on Exposure and Metering on 13th May.