Nhìn chung, bộ lọc giảm tiếng ồn là một bộ lọc bắn hữu ích đó là tốt hơn trong việc giảm tiếng ồn trong các hình ảnh có nguồn gốc như nắm bắt được kỹ thuật số, chứ không phải là giảm tiếng ồn hạt phim ảnh quét 35mm. Bộ lọc này chủ yếu được thiết kế để nhắm mục tiêu các vấn đề song sinh của tiếng ồn kỹ thuật số độ sáng, giống như một hạt speckly rất tốt, và tiếng ồn màu sắc,. | Chapter 5 Image editing essentials Multiple adjustment layers When you add multiple adjustment layers you can preview how the image will look using various combinations of adjustment layers and readjust the settings as many times as you want before applying them permanently to the photo. For example you might want to use multiple adjustment layers to apply different coloring treatments to a picture. Instead of producing three versions of an image all you need to do is add three adjustment layers each using a different coloring adjustment and switch the adjustment layer visibility on or off to access each of the color variations Saving Layer Comps can help here . While it is possible to keep adding more adjustment layers to an image you should try to avoid any unnecessary duplication of the layers. It is wrong to assume that when the image is flattened the cumulative adjustments will somehow merge to become a single image adjustment. When you merge down a series of adjustment layers Photoshop will apply them sequentially the same as if you had made a series of normal image adjustments. So the main thing to watch out for is any doubling up of the adjustment layers. If you find you have a Curves adjustment layer above a Levels adjustment layer it would be better to try and combine the Levels adjustment within the Curves adjustment instead. Of course when you use masked adjustment layers to adjust specific areas of a picture you can easily end up with lots of adjustment layers. One potential drawback of this is that it may slow down the screen preview times. This slowness is not a RAM memory issue but to do with the extra calculations that are required to redraw the pixels on the screen. If you think this is happening then try switching off some of the adjustment layers while you are editing the photograph. To summarize the chief advantages of adjustment layers are the ability to defer image adjustment processing and the ability to edit the layers and make selective .
