Right ISO for Your Picture
Have you even considered changing the ISO sensitivity on your camera? If you don’t know what ISO sensitivity refers to, you may want to consult your camera manual for a base point understanding about that and how it works. In short, changing the ISO setting on your camera changes the sensitivity to light, the lower number that you set the less sensitive to light (and conversely the higher the number the more sensitive it becomes).
Why change ISO?
You may wonder why it is necessary to make change of the ISO sensitivity; in fact, your camera just picked a suitable ISO sensitivity probably the best for your pictures when you are shooting in automatic mode. When you discover the limitation of the automatic mode, you will start to care about what ISO sensitivity should be used when shooting in other modes.
This is useful when you are shooting in different lighting situations - particularly when there is low light and you might not be able to use a flash (you’d bump up your ISO setting in this case), and this is just the beginning why you would want to shoot at higher ISO.
The Inside Story
The only cost of increasing ISO is that as you do it you’ll notice that the “noise” or “grain” in your shots also begins to increase. Thus, the rule is simple - choose the lowest ISO possible for smooth and grain-free shots. The latest generation DSLR cameras today has very nice result at ISO 400 and lower sensitivity, you may consider the output are “noise-free” setup. You have start to concern about anything above ISO 400 … full article.