| Photoshop Tutorials » Effect » Noise |
First, we're going to convert the layer to a smart object. By converting the layer to a smart object, the filters that we'll apply later will become smart filters; always editable like layer styles. If you're not using Photoshop CS3, you can skip this step. You may want to duplicate the layer by pressing Ctrl+J to keep a backup of the original image as a layer.
A digital photographer must endure digital noise. However, this doesn't mean you have to accept all kinds of noise in your photos. There is a variety called color noise. This you can remove even if you don't have a dedicated menu command or effect in Photoshop. This article offers a brief insight into the world of noise filtering. By modifying or enhancing the steps of the procedure according to your needs, you can develop your own, more effective methods.
Noise removal is really an inexhaustible topic. Actual removal procedures are several, even if not infinite in number. In accordance with this theory, we're offering a second, simpler and perhaps even more effective procedure for removing color noise. All we use for reducing this annoying phenomenon are Photoshop's amazing layer management, general effect modes and the Gaussian Blur feature. Beginners are encouraged to follow!
Digital noise in photos taken with digital cameras is random pixels scattered all over the photo. It is a similar effect as �grain� in film photography and it degrades the photo quality. Digital noise usually occurs when you take low light photos (such as night photos or indoor dark scenes) or you use very slow shutter speeds or very high sensitivity modes. When taking pictures with a digital camera an electronic sensor (also known as a CCD) built from many tiny pixels is used to measure the light for each pixel. The result is a matrix of pixels that represent the photo. As with any other electronic sensor the CCD is not perfect and includes some noise (also know as white noise to hint on its randomness attribute). In most lighting the light is significantly stronger than the noise. However in extreme scenes where the light is very low or when a high amplification is needed noise levels can become significant and result in pixels in the photos that include more noise data than real photo light data. Those pixels usually appear as random dots or stains on the photo (for example white dots scattered randomly on the photo). Understanding digital noise in various scenes: low light (night photos or dark scenes): when the scene is dark the amount of light measured by each pixel of the CCD is low. When the light intensity is very low it can become too close to the level of noise naturally found in the CCD. In such cases some pixels can appear as noise because the noise level measured for them is significantly close or higher than the actual light intensity. slow shutter speeds: when the shutter is kept open for a long time more noise will be introduced to the photo. A slow shutter speed translates to the CCD integrating more light per pixel. The effect can be easily understood as the CCD �accumulating� light in each pixel and measuring the total light over the shutter period of time. However at the same time the CCD is also �accumulating� noise. For that reason in slow shutter speed photos some pixels will appear as noise because for these pixels the amount of noise integrated is significantly close to or higher than the actual light measured. high sensitivity modes: high sensitivity in digital photography is implemented by mechanisms that result in amplification. The CCD amplifies the measurements it takes. However there is no way to just amplify the actual photo light that falls on the CCD pixels instead the noise and the actual light are both amplified. The re...