If you didn’t get enough from my first POST on ISO, here’s little more

So you now understand that ISO defines your camera’s sensitivity to light. You know that a lower number means that it is less sensitive and a higher number means that it is more sensitive. So now the question is, why don’t you just use the most sensitive ISO all the time? Things could be so much easier, just keeping on one setting all the time and changing everything else according to that. You could do all your indoor shots without flash, you wouldn’t have to worry about low light situations, and even in brighter light you could have one less thing to think about, right? Well, the problem is that when you change your ISO, you are also changing the quality of your image. When you have a low ISO (ex. 100), the quality of your image is top notch! With film, you would hardly have any film grain, and with digital hardly any noise. But when you use a higher ISO (ex. 800 or 1600) the quality of your photograph is going to go down. You will have a lot more grain or digital noise in your photograph. Continue reading →

When I am teaching my photography class, one of the first things I like to start with is understanding what ISO is. ISO is the same as Film Speed, but alas film is not around the way it used to be. However, the principles that were used on film cameras are the same as what is used in digital cameras. The difference is that you can change the ISO in camera with digital, but with film you have to buy a specific type of film and the whole roll would be that particular film speed. When understanding ISO, the first thing you should know is what exactly it does. Continue reading →