Join Michael Ninness for an in-depth discussion in this video Roughening or pointilizing edges with Dissolve, part of Photoshop Blend Mode Magic.
The Dissolve blend mode is one of those blend modes you probably won't use very often but it does have one interesting use case that I kind of like. It's a way to roughen or pointillize some edges. To begin, you are going to do a technique that you are going to use a lot with blend modes that's called a self-blend, and all that means is you are going to duplicate a layer, the existing layer in this case and then just change its blend mode. You can change it to whatever blend mode you want. In this case since we are talking about Dissolve, we'll do Dissolve. To duplicate a layer, Command+J or Ctrl+J on Windows and this is what we have done to setup our self-blend. We'll just change our blend mode to Dissolve.
Now at first glance, it's not going to look like it's done much, or in this case anything because I don't have any change between the two layers. Dissolve is not calculating any sort of tonal differences between the two layers and doing a sort of blend. It's actually introducing a random pixelization and opacity effect which we won't really notice until we have some sort of pixel difference between the two layers. So to begin that we are going to get our Move tool. If we don't have it already, V for the Move tool. I am just going to offset my layer slightly. I'll use my Down Arrow, tap it once and my Right Arrow, tap it once, just to do a one-pixel shift. I'm going to do Command+Plus or Ctrl+Plus to zoom in and we'll hold down the spacebar to pan just a little bit. I want to be able to see my edges here a little bit.
I mean the edges of the flower petals. Again I'm not seeing much difference yet. I have just done a one-pixel shift. But if I combine this blend mode with an opacity change, so I have got my Move tool selected. I'm just going to press the number 5 key to change the layer opacity of Layer 1 to 50%. Now I have got quite a big difference between the two layers and the blend can actually occur. You will see I'm getting this nice roughening or pastel or pointillism effect along those edges. So it's kind of a neat effect.
If I turn the Background layer off, you will see what I mean by it's punching holes through the top layer and giving this little random noise patterns. So those are actually transparency holes you see wherever there is white there. So you're actually seeing through to the underlying layer and because it's roughening up the edge there, it's giving you this nice rough blend. If I zoom down, Command or Ctrl+Minus, you can control this by offsetting it more, playing with the different layer opacity. So if I use my arrow keys just to offset this one or two more pixels in either direction. I can lower the opacity or increase the opacity, so maybe type in 8 for 80% or 3 for 30%.
It's up to you. You have a lot of flexibility here on how to do the actual blend. If I want to have more differences, you can also introduce a blur on this layer. So if I go to Filter > Blur > Gaussian Blur and just start with a very lower opacity, let's say just enough to start randomizing it even further. We have a lot of leeway here in using these basic ingredients. We'll just go with the two-pixel blur and click OK. And to see the before and after, we'll just turn that top layer off. There is where we started, turn it back on and there is where we ended up. The fact that we have done it as a duplicate layer, a self-blend, means we have never destroyed our original background layer. If we don't like our results, we can simply delete the layer and start over.
But there is, you know, hopefully an interesting use case for the Dissolve blend mode. You won't use it that often, but it is pretty cool when you want to make this rough pastel-y type effect along the edges of your image.
- Understanding the three must-learn blend modes
- Adding texture overlays
- Recovering detail using Luminosity and Pin Light
- Enhancing highlight and shadow details
- Instant dust spot removal
- Using Overlay to add textured type
- Simulating film grain
- Adding antique color effects
- Combining adjustment layers with blending modes