Sometimes there just isn’t that much Light around and you need to crank up the ISO to capture the scene you have envisioned When you increase your ISO on a digital camera, your processor amplifies the signal it receives from the sensor to make it stronger, much like an amplifier on a stereo, it makes a quiet signal much louder. The downside of using a high ISO is that artifacts in your image also magnified. These artifacts appear as Color Noise and Luminosity noise.
We cover using the Surface Blur, dust and scratches, and Reduce Noise Filters. Learn how to use a combination of these Filters along with blending modes, Opacity and Layer Masks to maintain a high Level of control when removing the Noise from your image and to preserve details in the important parts of the image.