Digital Camera and the Role of ISO

ISO isn’t new to the world of cameras. If you can remember back to the day of film you could purchase 100, 200, 400, 800 ISO film. Today, on your digital camera you can change the ISO with just the press of a button. So what is ISO? 

The ISO speed is a measure of your camera sensor’s light sensitivity. The lower the number the less sensitive while the higher the number the more sensitive. If you were to take a photo of a subject using 100 ISO and then take a photo of your subject using 800 ISO or higher, you would discover:
 
* The photo with the lower ISO speed (slower) will force your camera to use a slower shutter speed when you take the photo. On the other hand, the photo that is taken with the faster ISO speed will have a much faster shutter speed. If you are using a faster ISO you’ll be able to freeze that moment in time. If you have poor lighting, choose a slower ISO.
* The slower ISO speed photo has less noise than the photo taken with a faster ISO. We should mention that DSLR’s perform better than the point and shoot cameras do. Therefore, you might find yourself in a situation where you have to trade off between usability and quality when lighting is poor. 
* You should use the minimum ISO speed to achieve adequate shutter speed. This is usually 1/focal length for most pictures. There might be a few stops where you will need to slow the image stabilization or make it faster such as with action shots. Keep in mind it is better to have a couple of pixels that are discolored is a lot better than all encompassing defocus or blurred images. Some digital cameras are able to pick an ISO, which is quite handy functionality.

Unless you have an understanding of how ISO works, you will have trouble making the right choice for the conditions you are taking photos under. Your ISO is as important as understanding your flash and in many ways it is more important. 

The higher the ISO the larger you will be able to print our photo, but remember the higher the ISO the grainier the photo is going to be. Choose the appropriate ISO to get the clearest pictures. With digital cameras a lot of things have gotten easier and the ISO is one of them. Now you too can be a photographer. 
