Recently, many of my GCC students have been asking me the same question–”If my pictures are overexposed or underexposed, how do I decide which part of exposure to adjust? The aperture or the shutter speed or the ISO?”
The Answer: It all depends on what kind of picture you are trying to take.
Do you want full depth of field or shallow depth of field? Do you want a lot of detail in the photograph? Is your subject moving around? Do you have a tripod available?
Here are a few examples of how you would adjust your settings based on what type of photograph you want to take:
If you are trying to take a picture where you want to keep a lot of detail and depth of field (like Landscape and nature photographs), then you would adjust the shutter speed. Why? To keep the quality high, you want a slower ISO like 100 or 200. To capture all the detail in the foreground, middle ground and background, you need a smaller Aperture. So ideally, you would be using a tripod so that means you can have a slower shutter speed since your subject isn’t moving–therefore Shutter Speed is where you would make the adjustments if your photograph is underexposed or overexposed.
For Sports, you want to keep a fast shutter speed to stop the action and you want a fast ISO but not too fast that you will get too much visual noise so you often adjust your aperture. In Sports, it is preferable to have a shallow depth of field so you can use an Aperture wider than F5.6. Typically, sports photographers use Shutter Priority mode so they can set the camera to a fast shutter speed and the camera will automatically adjust the aperture for you.
