Image Quality Tests (ISO Settings)
The Kodak DX7590 offers an ISO range of 80-400 in four manual steps (80, 100, 200, 400). You can also leave the ISO set to "Auto", allowing the camera to set the most appropriate choice depending on the scene and other camera settings.

ISO is similar to film speed. The higher the ISO rating, the more light sensitive the camera's image sensor becomes. Similar to film, which exhibits increased grain at faster film speeds, digital cameras also exhibit grain, which is often referred to as "noise." Higher ISO settings allow the camera to use faster shutter speeds, important when trying to capture motion, especially in less than ideal light. Since each increase in ISO also adds an increase in "noise," you will need to find a balance between shutter and ISO sensitivity - thinking ahead as to how the image will be used. If large prints will be required, then you may want to stay away from higher ISO settings due to this increased noise.

ISO 80 | Aperture: f/2.8 | Shutter: 1/60th	ISO 100 | Aperture: f/2.8 | Shutter: 1/80th

As you can see from the samples above and below, the DX7590 takes pictures with very little noise or "grain" when shooting at an ISO settings of 80 or 100. At ISO 200 and 400, more noise is evident, but still very low when compared to other large-zoom cameras in its class. Noise often shows up in solid colors as well as in shadow areas of a scene.

ISO 200 | Aperture: f/2.8 | Shutter: 1/160th	ISO 400 | Aperture: f/2.8 | Shutter: 1/320th

Whenever possible, it is smarter to increase natural lighting before increasing the ISO setting (for increased light sensitivity of the camera.) Setting a higher ISO does allow the camera to use higher shutter speeds, which is beneficial for capturing moving subjects without blur such as when shooting indoor sports (basketball, gymnastics, hockey, etc.), but the trade-off is some loss of image quality due to the increased ISO setting.