What is ISO

ISO (sensiti.pdf)
ISO is the number indicating a digital camera sensors sensitivity to light. The higher the sensitivity, the less light is needed to make an exposure.
Digital cameras automatically select the ISO but most have a setting to change it manually. Auto ISO generally works best for bright scenes.
Shooting at a lower ISO number requires more light than shooting at a higher number. Lower numbers result in images with the least visible noise, which is desirable.
The higher the number, the more noise. The amount and degree of noise varies from camera to camera.
Digital Single Reflex Cameras (DSLR), because they have larger sensors, are best for Producing noise-free images. however, some consumer digital cameras now have improved sensors that produce acceptable images at higher ISO.

ISO settings
Auto iso-Digital Camera automatically sets the ISO speed according the brightness of the scene, increasing or decreasing the sensitivity. User has no control over which ISO number is used.
ISO 50-80-for taking photos in bright light; excellent for close-ups, landscape, and portraits. produces fine detail and image quality.
ISO 100-for extra sensitivity with little, if any, CED image quality.
ISO 200-cloudy and
Overcast days. Acceptable image quality, with some visible noise.
ISO 400-suitable for indoor photography whether or not a flash is used. Useful for "stop-action" and sports photographs. Most compact digital cameras produce high to very high image noise.
ISO 800,160 0 and above-useful for taking photos in very low light, or outside in good light when increased shutter speeds are required. results can be disappointing when shooting at these ISO numbers with compact digital
Cameras, so take test photos before photographing an important event.
Changing ISO can change the aperture and shutter speed, depening on what exposure mode is used.

The higher the ISO, the shorter the exposure time.
That is to say, the lower the ISO value, the more delicate the photo, but if you take a photo in a dark environment and do not need to light up, you need a high ISO to make the exposure, ISO is twice as high, and the exposure time is reduced by half, to solve the problem of insufficient light.
Add a sentence ·~ What do you usually see with thousands of ISO cameras? They are actually not good, because we rarely take pictures in the dark, and there is a flash in the dark, unless you are a spy ~ The higher the Haha ISO, the rougher the image.