What is ISO in digital photography? And other ISO FAQs.
ISO is one of the core concepts of photography and one of the most important parts of the exposure triangle. The better you get at managing ISO, the more you can control the outcome of your photos. That’s why we’ve put together this handy list of FAQs about ISO.
What is ISO in digital photography?
ISO in digital photography is your camera sensor’s sensitivity to light. Adjusting the ISO will either increase or decrease the perceived light in your photo. When you increase the ISO, your camera’s sensor will capture more light, and the photo will become brighter. When you reduce the ISO, less light is captured and your image will become darker. Sensitivity ratings for cameras are standardized; ISO 100 is the same regardless of the camera you’re using.
How does ISO affect a photo?
ISO increases or decreases the brightness of a photo, but it can also increase the presence of visual noise in your photo — variations in color and brightness that result in graininess. This is why it’s not recommended to adjust the ISO alone.
Most of the time, you’ll need to widen the aperture and slow the shutter speed of your camera when you increase the ISO to reduce noise (the three sides of the exposure triangle mentioned in the intro). Noise can be both good and bad — it just depends on the look you’re going for.
What is a good ISO for a camera?
The best ISO for your photo will depend on the lighting you have along with your camera. As a best practice, you’ll want to start with the lowest ISO possible for the conditions you’re shooting in.
When there’s a ton of light, you’ll want to use a low ISO, like 100. For medium amounts of light, try upping it to the 600–800 range. If light is scarce, turn it up higher. The benefit of having a digital camera is that you can see the photos in real time and adjust the ISO to meet your needs.
What’s the difference between ISO and shutter speed?
ISO refers to how sensitive the camera’s image sensor is to light. Shutter speed is the length of time that the camera’s shutter remains open, exposing the sensor to light.
How does ISO affect shutter speed?
When you increase the ISO by a full stop (doubling the ISO), the shutter speed will also double. The shutter speed is affected in the same way when you decrease ISO. Let’s say your ISO is set at 100 and your shutter speed is 1/125 sec. If you increase the ISO to 200, your shutter speed will increase to 1/250 sec to maintain the same amount of light hitting your sensor.
When is ISO too high?
ISO is too high when it causes excess noise in a photo or when it overexposes a photo. Always try to use the lowest ISO possible, and don’t forget to balance ISO with your aperture and shutter-speed settings.
What ISO is good for low light?
When shooting in low light, you’ll need a higher ISO, but the exact setting depends on your camera, the lighting, your aperture, and your shutter speed. Try to start with an ISO of 400 and do a test shot. Increase the ISO and adjust your shutter speed and aperture as needed. The more you shoot in low light, the more you’ll better understand how your camera performs and the settings you’ll need to use.
How do you reduce noise caused by high ISO?
Noise in photos can show itself in two different forms. Chroma noise appears as small specks or blotches of color, while luminance noise appears as graininess. To reduce noise, always use the lowest ISO you can, or try using Auto ISO. In the auto setting, your camera will automatically adjust to the lowest ISO setting possible for the shooting condition. Most cameras will allow you to set the range, and the camera will take it from there.
Conclusion.
The best way to get a better understanding of ISO and its effects is to shoot more. The more you experiment with ISO, aperture, and shutter speed, the better you’ll understand the settings that give you the images you want. No matter what type of photography you do, learning how to use ISO is crucial to improving your photos.
