ISO stands for the International Organization for Standardization. It’s an organisation that sets and maintains industrial and commercial standards for the photography market and various other markets. The ISO standard was created in 1974 by combining previous camera standards ASA and DIN. Here we will discuss how this camera standard is important for photography and how users can adjust the same to get better photos.
What is exposure in photography?
Users should be aware of exposure before understanding ISO. The amount of light per unit area that reaches the frame of photographic film or the surface of an electronic image sensor is known as exposure. Users have to consider three main settings while exposing a photograph — the aperture, shutter speed, and ISO. It is also commonly known as the “exposure triangle” and users need to precisely balance all three factors to achieve a well-exposed image.
What is ISO in photography??
ISO was initially used as a rating to measure the light sensitivity of a photographic film. The range of ISO started from 100 and as the rating increases, the film gets more sensitive to light. However, with the rise of digital photography, the same term and standards are now used to measure the light sensitivity of a camera’s sensor.
How is it measured?
ISO is measured in numbers, which are usually in multiples of 100. Earlier, manufacturers used to stick to doubling the value where the range went from — 100, 200, 400, 800, 1600 and so on. But things have changed with modern digital cameras. Modern cameras have introduced smaller adjustments for better refinement of images and ISO measurements like 125, 160, and others are more common in cameras nowadays. However, the concept of increasing or decreasing the value is still the same. ISO 400 is two times as sensitive as 200, which is also double sensitive compared to 100.
How is it used in photography?
So, ISO in photography refers to a sensor’s or film’s sensitivity towards light. If you put your camera in a lower ISO setting, you will either need more light (bigger aperture) or a longer shutter speed to get the proper exposure for your image. On the contrary, if you increase the ISO setting, the camera sensor becomes more sensitive to light, which allows you to shoot in low light conditions by using a faster shutter speed or a tighter aperture.
Disadvantages of higher ISO
As discussed earlier, a higher ISO setting will make a camera’s sensor more light-sensitive which will make the image brighter. However, increasing ISO creates more grain or noise. Some experts also think that a higher ISO can also deteriorate dynamic range and colours. So, it is important to maintain the ISO as low as possible when there is enough light.
Some DSLR cameras come with a full-frame sensor, which is capable enough to handle noise. On the other hand, smartphones usually come with smaller sensors and the differences between low and high sensitivity levels are more visible.
Why should you maintain a low ISO?
It is advisable to increase the ISO only when it is necessary as a lower ISO will help you create a better-looking image. You can try to tighten the aperture or set a slower shutter speed if there is not enough light. If both these parameters fail to deliver the desired output, only then you should increase the light sensitivity.
There are other things that you can try to maintain the ISO as low as possible. These steps include adding artificial light to the scene or using a stable tripod to shoot with slower shutter speeds.