Home > Taking Photos > Advanced Techniques > Adjusting ISO
Adjusting ISO
Digital cameras are usually set by default to automatic ISO. The camera automatically sets the ISO according to light conditions: the brighter the light, the lower the ISO; the lower the light, the higher the ISO.
Many users prefer to manually adjust the camera's sensitivity to light. It gives them some control over the amount of noise that may appear in an image. In some cases, you can avoid using the flash by increasing the ISO.
ISO and noise
On many consumer digital cameras, selecting an ISO number above 100 produces little visible noise. Test each ISO number under a variety of lighting conditions until you become familiar with the noise your camera produces at each setting.
If images are noisy, noise reduction programs do an effective job at eliminating some of it, though fine detail may be sacrificed.
| Low ISO settings | High ISO settings |
| ISO 50-100 | ISO 200 and above |
| More light needed | Less light needed |
| Less noise | Increased noise |
| More image detail | Less image detail |
| Larger aperture +/or longer shutter speed | Smaller aperture +/or faster shutter speed |
When deciding whether or not to use an high ISO number, keep in mind that the visual presence of noise is often barely noticeable when images are reduced in size for printing and/or viewing on a computer.
