Your Camera’s ISO Settings

by William Lulow

The camera’s ISO setting is a tool that controls the amount of light entering the camera by setting its sensitivity to light. ISO stands for INTERNATIONAL STANDARDS ORGANIZATION. This is an international group of people who decide what standards the world will use for most items that require numeration of some sort. The lower the number, the less light the camera “sees.” So, an ISO setting of 100 will be less sensitive to light than a setting of 1000, say. If you are shooting in a situation where there is very little light, (at night, for example), you might need to use a higher ISO number so that the camera can “see” more light. In many cameras equipped with a built-in flash, if you don’t change the ISO number, the flash will automatically pop up to add light to the scene. This would be undesirable in shooting a sunset, or a concert. So, if you don’t want to use the flash, you would need to increase your ISO setting.

The ISO setting is really where to begin your exposure settings. But, you need to decide what you are willing to sacrifice if you use a higher ISO number, because as you increase your ISO setting, you begin to decrease the quality of the images. Higher ISO settings introduce some “noise” or “grain” to the image. The higher the ISO setting, the greater sensitivity to light will be affected but also the greater the graininess of the image. If you are in a situation where there is very little light, you may decide to sacrifice some quality in the image for the chance to make any image at all! This was the case the other night while I was shooting a band performance. Most concert venues have stage light that highlights the performers. This place had no such light. So making images there was extremely difficult, at best. Here’s one example:

Here, the light on the musician’s face and the light reflecting off the guitar were very difficult to balance and needed some help from Photoshop.

Here’s another where the light on the musician’s face was almost negligible and as he looked down, it was even less. Some of these images were shot at ISO 2500 or 3200. Usually, when I shoot performances, I like to keep the ISO setting at no more than 2500. Because at much more than that, you will begin to see some breakdown in image quality.

This one was shot at ISO 2500, but the instrument was darker and therefore did not reflect more light than the singer’s face. Here the detail was pretty good and the exposure was fairly accurate. (All readings were made with the camera’s meter in center spot mode with “Back Button” focusing. Some images were underexposed by 1 stop when the subject was under the one bright light at this venue).