Page 1 of 1 Noise in images is an odd thing in digital images. Most folks want to get rid of it, some use it creatively, and others like the 'feel' of it. Note that this is completely different than film grain which is a physical characteristic of the actual film and development process. We're talking here only about noise, the kind of dots and artifacts you get in current digital images.
While you will probably find lots of articles on how to reduce noise and some that use Photoshop's noise filter as a starting point for other effects, you'll have to go some to find information on using noise creatively, or generating it for different looks. What I hope to show you is the latter of these first in this article, then in the second part, we'll look at some creative uses.
We'll keep things really simple this time, using the following tools:
You might notice that I list a specific filter, then 'Various'. The reason is that you will be choosing your own filters to explore noise and texture.
Great question! I thought about this article after working on some photorealistic composites, and trying the usual methods to generate noise or grain in shadows, with the goal of matching things up for consistency. In doing so, I got bored and tried some variations on getting to the same result. What came out of that was a fun little excursion in generating textures, starting from the noise filter.
You might still be wondering why this is of any interest. All I can say is take some time to try things out. You may have a project that needs a little 'something', but you don't have any ideas. Picking a technique and running with it sometimes yields interesting results, but more often sparks other ideas. While you can use the material here directly, you may find the greatest benefit is in getting the juices flowing.
Great! Let's start with a basic, blank document. I'm using a square canvas with a transparent background, but it really doesn't matter at this point. Keep this in mind, though:
Pay less attention to the settings, and more to the process!
Ok, fill your layer with 50% Gray (Edit > Fill > 50% Gray). We're going to look first at getting a little control over the process so we can move around with our creative ideas more quickly. Add 30% noise to your layer by choosing Filter > Noise > Add Noise, and adjusting the slider to roughly 30%, then choose Gaussian for the method. You should get something like this:
Figure 1
We just added some noise, so let's see how Photoshop handles reducing noise, shall we? In the same Noise filter menu, now choose Reduce Noise. Tweak the settings and use the Preview check box to see before and after. Here's what mine looks like with the following settings:
Strength: 10
Preserve Details: 0
Sharpen Details: 100
Remove JPEG Artifacts selected
(Color Noise doesn't affect this because it's all gray scale)
Figure 2
Notice the funky little lines that are implied, like a bucket of tiny worms. This is a result of how Photoshop views noise: as tiny but high-contrast regions, nearly to the pixel level. By reducing noise, we have forced Photoshop to make a decision about the patterns, and it did the best it could. The result is an interesting texture that might be used as a bump map for skin:
Figure 3
Let's check out the blur and sharpen effects, next. Generate your noise layer again with the same settings above. Now use the Median filter (Filter > Noise > Median) with about 4 pixels, and then drop some Unsharp Mask (Filter > Sharpen > Unsharp Mask). I cranked it up for Figure 4:
Amount: 200%
Radius: 15 pixels
Threshold: 29 levels
Figure 4
Looks like concrete, doesn't it? Pay attention to how the sharpening takes what was left from the Median filter and bumps up the contrast in local regions. When pixels clump together, the sharpening makes the edges more clear, causing little random islands to jump out. From here you could create a nice asphalt or road texture, as in Figure 5:
Figure 4
If you plan to experiment, give yourself a little break from repetition by either duplicating your base layer before trying something, or create an action to generate the layer for you. Also, pay attention to your history steps if you find something you like!
I've shown you two starting points for getting a handle on how noise works, but for it really to click, you need to roll up your sleeves and dig in. Start with the same noise pattern first, then apply various filters in different orders to see what happens. If you find something interesting, make a note of the steps and let the process take you some place. After a few tries, you may start to come up with ideas about simulating specific looks. Go for it! Just don't get too frustrated or you'll not want to come back.
As you work, keep an eye on how the pixels and filter interact. You'll develop a feel for things like clustering, size, and patterns. Blur filters are great for generating lumps, and you can apply levels and curves to modify the tonal ranges. Stick to grayscale noise for now until you are comfortable with how stuff works together. When you add color in the mix, you can really take a lot of control over the final result, but one thing at a time, ok? ;)
So, try out those 'Artistic' filters you've shied away from, and maybe hit up Reticulation under the Sketch filters. If you need something to work towards, head over to flickr and look at some old photographs, textures and film grain samples and see if you can't get something similar.
See you next time!
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Keywords
photoshop, noise, filter, layers
