WHAT IS ISO?
ISO - defines camera sensitivity
while shooting the image. ISO is simply a camera setting that will brighten or
darken a photo. If you increase your iso number, your photos will grow progressively
brighter. If you decrease you will get perfect detailing and perfect light to
the image as I have shown above.
The sensor size of the camera defines the iso
performance. if you don’t have enough
light in the subject don’t force your camera to shoot in high ISO because it
will turn the image with lots of grain and it will lose the details of the
picture.
At night you will not get sufficient light to click the landscape or stars in that case you have to set your ISO high like 1600 or 3200 to expose the image and you have to use a larger shutter speed like 10s 30s and you must set your aperture numerically low like f/3.5 f/2.8 as shown in the image below:
Note: To click the perfect well-lit image in daylight set low ISO will help you to get the high-quality image.