In order to perfect a picture’s exposure, one must learn the three sides of the exposure triangle. Understanding aperture, shutter speed, and ISO is the key to being a proper, professional photographer.
To understand the relation between the elements, you need to know how each element works first.
The aperture is the first side of the exposure triangle. It refers to the lens' opening; the wider it is, the more light the camera sensor will record.
A wide lens’ opening results in increased exposure. Conversely, as the aperture narrows, the image becomes less bright, reducing exposure.
A wide-aperture lens lets in more light, allowing you to utilize a faster shutter speed or lower ISO to achieve a properly exposed photograph. A narrow aperture, on the other hand, allows less light in, necessitating the use of a higher ISO or a slower shutter speed to compensate.
Another effect of the aperture is the depth of field. The larger the aperture, the smaller the concentrated area will be. Meanwhile, using lower apertures will result in a larger focused area. When altering the exposure triangle, this should also be considered.
While aperture is crucial in exposure triangle photography, it’s highly influenced by the following variable, shutter speed.
A camera's aperture opens when the shutter button is pressed. The shutter speed of the camera controls how long the aperture remains open.
The greater the shutter speed, the more light is captured by the camera sensor, and the longer the final exposure. Shorter shutter speeds, on the other hand, allow less light to reach the sensor, resulting in a less exposed final image.
Another consequence of shutter speed that must be considered when balancing the exposure triangle is motion.
Shutter speed, like the other variables of the exposure triangle, affects not only exposure but also other visual elements. Motion blur, for instance, is affected by shutter speed.
You can photograph moving things or shoot with a rapid shutter speed. Additionally, long exposures can be used to photograph stars, waterfalls, and rivers with the silk effect.
Fast shutter speeds, on the other hand, will produce crisp images. It will, however, allow less light through, making it unsuitable for darker images. When filming a video, the same issue occurs.
The exposure triangle's final variable is ISO. You can think of ISO as the digital sensor's sensitivity, although it is a lot more complicated than that.
ISO refers to the camera's ability to amplify the light it captures. The aperture of the lens and the amount of time the shutter is open are how digital cameras catch light naturally. ISO enhances the image's brightness artificially.
The ISO scale, like the shutter speed, is simple to comprehend. A shift of one division doubles the ISO and results in a one-stop increase in exposure. A half-stop reduction in ISO equals a one-stop reduction in exposure.
Because the camera captures clear shots only under optimal lighting circumstances, a low ISO value is good for the camera when there is lots of light.
Higher ISO values indicate that the sensor does not require as much light to achieve proper exposure. Low ISO values suggest that the sensor will need to gather more light in order to complete the exposure.
When working in low light, you're using the widest aperture and slowest shutter speed to gather as much light as possible. The only option, in this case, is to increase the ISO.
By increasing the ISO, you can work with less light. Excessive ISO, on the other hand, results in more noise and less detail.