ISO, which means as International Organization for Standards, is a measurement of a digital sensor’s light sensitivity. A bigger number signifies greater sensitivity and the capacity to capture more light. ISO settings can range from 100 to 6400 depending on the specific camera used. ISO 100, ISO 200, ISO 400, ISO 800, ISO 1600, ISO 3200, and ISO 6400 are the most popular ISO settings found in digital cameras. When you double the ISO speed, the brightness of your photographs will likewise double, indicating that the values are relative to one another.
When we change ISO, we do not change the size of the pixel; rather, we electronically increase its sensitivity, or, in other words, we increase the voltage to the sensor. Internally performed by the camera’s software and sensor, changing ISO is comparable to increasing the gain on a microphone.
On a sunny afternoon, you won’t have any light problems, so you can set your ISO to a much lower number. Between taking pictures during the day and at night, you will have to play around with the ISO values to find the best balance between exposure and image noise. Here is a basic reference for common ISO values based on lighting conditions:
- Bright, sunny day outside: ISO 100 or 200
- Cloudy days, indoors, or window light portraits: ISO 400
- Indoor photography without flash: ISO 800
- Reserved for very low light conditions: ISO 1600
Digital noise is an unfortunate side effect of increasing ISO. The higher the ISO, the greater the amount of digital noise added to the image. Because you want your photographs to have the maximum amount of clarity, you need to pay attention to the ISO setting. Keep in mind that the higher the ISO, the lower the light level your camera can tolerate, but the higher ISO will also increase the amount of visible noise or graininess. Find a balance between how dark it is and how much noise you can tolerate in your photographs without damaging them. Also, be sure to have a tripod on hand if you will be photographing in low-light conditions in order to reduce the movement that could cause the image to become blurrier. You will want to do everything possible to achieve sharpness, even if it means increasing the ISO.