If you are new to photography or have just taken the plunge and gotten a camera with manual controls, you may be a little overwhelmed by the various options you can control. One of the biggest issues new photographers deal with is to nail the exposure in their photos. A major reason for this issue is the confusion they have to face when choosing between aperture values, ISO values, and shutter speeds, as all three have a direct effect on the exposure.
Understanding Aperture and Shutter Speed
The aperture number of your camera dictates how wide the aperture of your lens is open. The wider it is open, the more light the camera gets. But a wider aperture also causes your depth of field to be shallower, so it may not be ideal for landscape shots.
The shutter speed of your camera defines how long the shutter of your camera stays open while capturing a photo. The longer it is open, the more light enters the sensor and the brighter your image is. But a longer shutter speed also causes moving objects to get blurred, so it may not be ideal for shooting action.
Rely Lesser on the ISO
The reason you should rely more on altering these options to get your perfect exposure as opposed to cranking up the ISO is because a higher ISO, while making your image considerably brighter, causes a lot of noise to creep into your photos. These days, cameras have much better processors than before and noise levels are kept in control till very high ISO numbers, but noise will still find a way into your photos the higher you take the ISO.
So depending on the kind of shot you want, keeping in mind what kind of depth of field you’re looking for, try to rely more on the aperture value and shutter speed to get your shot, and keep your ISO to a level where you’re sure your camera can handle the noise.