I was listening to an interesting radio show. The topic was noise in audio signals. It got me thinking about noise in video signals and in photography. In print almost every photo needs to be sharpened a little to make it look right. This is largely a result of print resolution. It’s a fairly complex subject but typical picture resolution for a printed page needs to be about 300 pixels per inch, at least that’s what printers want. A photo’s resolution needs to be about double the line screen of the printed piece. Don’t worry too much about this because as I said its complex. This is interesting because often an image needs to be both sharpened and have noise added to look right on a printed piece. When I’m working on a painting I often find that transitions appear too sharp and the painting has an unrealistic appearance. Sharpening transitions can also add to the reality illusion but it’s a balancing act. I’ve noticed that in many cases I’m compelled to add some noise to make the painting look realistic. This noise might be blurred lines and some small brush strokes of various colours.
Its worthwhile noting that sharpening that we talk about in an application like Photoshop is simply increasing contrast of adjacent areas. OK it’s a little more complex than that. This link gives you a much better explanation:
This is a technique that artists have used for several centuries. An artist often enhanced the contrast with fine light and dark lines in adjacent areas. Here is another link that documents this technique in paintings.
Noise is also fundamental to our view of reality. The reality we see is not perfect, there is a lot of fuzzy aspects to our perception. So to elicit the ‘reality illusion’ as I call it, the image needs to incorporate some of this fuzziness. I usually blur the lines a bit, sometimes they are just blurry to start with and sometimes I need to consciously blur them. I also try not to make colours too pure or smooth particularly when they are side by side with other solid colour blocks.
Blurring the lines is easy I just slightly overpaint them with similar colours. Noise is a little more tedious, I generally add some small areas of similar or reflected colour to areas around the blurred lines. I don’t have any hard and fast rules about this I simply do it until the image starts to look real.