ISO

In very basic terms, ISO is simply a camera setting that will brighten or darken photographs and videos. As the ISO number is increased, the content will grow progressively brighter. For that reason, ISO can help one capture images and films in darker environments, or be more flexible about the aperture and shutter speed settings.

Unfortunately, raising the ISO has consequences. Content taken at too high of an ISO will show a lot of grain, also known as noise, which may ruin the subject. Therefore, raising ISO is always a trade-off. One should only raise their ISO when they are unable to brighten the photo via shutter speed or aperture instead.

The acronym 'ISO' stands for 'International Organization for Standardization'. However, camera ISO does not directly refer to the organisation that creates various technology and product standards. Ever since two film standards called ASA and DIN were combined into ISO standards in 1974 (later revised for both film and digital photography), they were referred to as one word 'ISO' from that point on. Although ISO initially defined only film sensitivity, it was later adopted by digital camera manufacturers with the purpose of maintaining similar brightness levels as film.

Not all camera have the same range of ISOs. The values consist of 100, 200, 400, 800, 1600, 3200, 6400 and 12800. The lowest native ISO on the camera is known as the 'base ISO'. This is a very important setting, because it gives one the potential to produce the highest image quality, minimising the visibility of noise as much as possible. Some older DSLR (Digital Single-Lens Reflex) cameras and a number of modern cameras, such as the Fuji X-T2, have a base ISO of 200, whereas most modern digital cameras have a base ISO of 100. Optimally, one should always try to use the base ISO to achieve the highest image quality. However, this is not always possible to do so, especially when working in low-light conditions.

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