Making a dynamic Dissolve effect

So here I am looking at the Dissolved circle from the previous exercise. Now the problem with it even though it's surrounded by this interesting dithered noise pattern is that I can't back off the effect, because after all I applied Gaussian Blur as a static modification. So I can increase the Blur value if I want to, just by pressing Ctrl+Alt+F or Command+Option+F on the Mac to revisit the Gaussian Blur dialog box, and I could take the Radius value up to let's say 100 pixels to really blast things out and then click OK.

But now I've applied another static helping of Gaussian Blur. Some other day when I'm working inside this file I can't back off the effect. What if you want to dissolve a layer dynamically? Well then you need to resort to a Layer Mask, and here's how. I'm going to turn off this Circle layer and I'm going to turn on the Mask layer which is a layer of solid white inside of a Layer Mask, so I'll go ahead and click on that Layer Mask thumbnail in order to select it and I'll once again switch from the Normal Mode to the Dissolve Mode and that will give us that slight amount of diffusion around the edge there.

Then I'll bring up my Masks Panel by going to the Window Menu and choosing Masks and I'll increase the Feather value. So I'll take the value up to a 100 pixels for example in order to blow that effect away, and then later if I change my mind all I have to do is return to the Masks Panel and set the Feather value to something else, such as my original Radius value of 25 pixels, in order to achieve this effect here. Between you and me I consider this an extremely good way to work. I do want you to know however that while it works for pixel-based layer masks this technique for whatever reason does not work with vector masks.

So I'll go ahead and turn off that mask layer, and I'm going to collapse my Color Panel just to give myself a little more room, and then I'll turn on the vector layer, click on its mask thumbnail in order to select it, change the Mode from Normal to Dissolve. Notice that we don't see any changes around the edges of that circle. Even if I increase the Feather value to something extreme such as let's say 100 pixels we still end up with some very smooth transitions. So that's just my way of letting you know that if you want to work with Dissolve then you need to be working with the pixel-based layer or in this case a pixel-based Layer Mask.

In the next exercise I'll show you how to use the Dissolve Mode to create an interesting text effect.