{"id":3003,"date":"2021-06-20T09:15:38","date_gmt":"2021-06-20T09:15:38","guid":{"rendered":"https:\/\/new-blog.artlist.io\/?p=3003"},"modified":"2022-06-12T09:05:44","modified_gmt":"2022-06-12T09:05:44","slug":"camera-iso","status":"publish","type":"post","link":"https:\/\/new-blog.artlist.io\/blog\/camera-iso\/","title":{"rendered":"Sensor Sensitivity: Understanding Camera ISO, EI & Gain"},"content":{"rendered":"

ISO is a measurement of sensitivity to light. It forms part of the exposure triangle in photography and filmmaking. Knowing what it is, how it works and the impact that it has on your work is crucial to being able to obtain the best possible exposure in every shooting situation.<\/p>\n

What is ISO?<\/h2>\n

ISO is the standard measurement for film stock\u2019s sensitivity to light. It is also sometimes referred to as \u201cfilm speed\u201d, with ISO 100 being slower than ISO 800. Don\u2019t confuse film speed with shutter speed or\u00a0frame rates<\/a>. They are all different things. A slower film speed means that film is less sensitive to light and therefore requires more exposure to make an image.<\/p>\n

\"camera<\/p>\n

ISO 100 is thought of as the \u201cbase ISO\u201d. Increase your ISO to 200 and you give yourself approximately another stop; you have effectively doubled the amount of light reaching the sensor. ISO 400 is 2 stops, or 4 times, brighter than ISO 100. By going to ISO 1600 you increase brightness by 4 stops.<\/p>\n

However, the increased sensitivity to light from faster film speeds will result in more grainy-looking images. The photosensitive grains that coat film are smaller and less sensitive to light with lower speeds; higher speed films have larger grains that can pick up more light. But being larger means that these grains are more visible in the final image.<\/p>\n

When it comes to photography and filmmaking, ISO means sensitivity. A higher ISO means more sensitivity but with it, more grain, too.<\/p>\n

Why is ISO called ISO?<\/h2>\n

The letters I, S and O in \u201cISO\u201d don\u2019t have anything to do with light, film chemicals or optics. They refer to ISO 12232:2006 (it used to be ISO 5800:2001 until it was updated in 2006), which is the International Organization for Standardization\u2019s yardstick for color-negative film. The International Organization for Standardization is headquartered in Geneva and is responsible for developing and publishing commercial, industrial and technical standards. Each of these standards is given a number prefaced by ISO. There are many other ISOs in the world, for example for roof load carriers on vehicles, but ISO 6:1993 refers to black and white negative film and ISO 2240:2003 is the measure for color reversal film.<\/p>\n

ASA vs ISO<\/h2>\n

ASA vs ISO? There\u2019s no difference. ASA refers to American Standards Association but the measurement is the same. Film with a speed of ISO 200 is the same as ASA 200. But since 1974, the standard term is ISO.<\/p>\n

ISO in a digital world<\/h2>\n

\"713\"<\/p>\n

Despite ISO referring to film speed and being rooted firmly in analog photography and filmmaking, its name continues to be used as a measurement of sensitivity to light in digital cameras. Digital camera ISO forms part of the exposure triangle together with\u00a0aperture<\/a>\u00a0and shutter speed that you adjust in order to shoot an image. When you dial in ISO 100 to your\u00a0DSLR or mirrorless camera<\/a>, its sensitivity to light should be the same as ISO 100 film.<\/p>\n

Your camera achieves this increased sensitivity by increasing the voltage and boosting the signal to the sensor. Much like increasing the volume on a static-y radio broadcast, this amplifies everything that the sensor sends to the processor, which includes the interference. Just as film ISO produces grain, digital ISO produces noise.<\/p>\n

How to choose an ISO<\/h2>\n

\"images<\/p>\n

While you still have an exposure triangle in filmmaking, one of its key features is fixed. Your shutter speed will be determined by your frame rate and cannot, therefore, be adjusted. Knowing how to select the best aperture and ISO for your desired exposure is, then, vital.<\/p>\n

Digital cameras are able to produce extraordinarily high ISOs, but of course, the pay-off for these is noise. As a general rule, you want to shoot with the lowest ISO you can.<\/p>\n

Let\u2019s say that you are shooting with a frame rate of 30 fps and therefore a shutter speed of 1\/60 second:<\/p>\n