Threshold

Hello fiddlers, and welcome back to another episode of Fable Academy. In this video, we're going to be talking about the Threshold utility.

We have our scene here, simple JPEG image. From here let's take with our layer selected to the top right into our effects panel. We're going to type out threshold, click, drag, and drop.

I will see that immediately things start to happen. A couple settings here. We've got the threshold, which will be the overall control. The softness being how aggressively the effect that takes basically the value A versus value B.

Change color, which means that basically it goes from a colored image to a black and white, and this allows you to select out of the highlights of the shadows.

Change alpha, is going to control the image and its transparency. Let's make this a little bit easier to see. We'll choose a background color of red, so you'll see when it shines through. We've got the invert tab here, which will be more visible once we affect the other two parameters.

And our global opacity, which will basically give us the 0 to 100% visibility on our effect.

So how does this work? Threshold basically is how much of a certain parameter is it choosing? If we go to the left, oh, actually you have to have one of these two options selected.

Let's start with color. This will make it black and white. If we go to the left, basically, it brings up the shadows and gives the prior to the highlights. And if we go to the right, it clamps down the values, making it completely opaque.

This can also be affected with the softness tab. If we go all the way to the left, you'll see, we get super sharp edges in our selection of highlights. We go to the right, it will soften it until basically it becomes a universal all in or nothing type of selection. What this is doing is it's clamping down values.

The next one that we can do is the alpha, and this is where the clamping will make a bit more sense. When you make it about the alpha, remember we made our background bright red. If we turn off the softness and we turn down the threshold, notice how most of our image is opaque.

As we go to the right and it sort of releases or declamps the higher values, it starts to erode the image so that the background plays through. If we soften this up, we can get these really nice, beautifully blended semi-transparent options.

Think of this as a levels adjustment for the luminance values of your layer. But having to do with the alphas.

If here we choose invert, notice that now the inverse of the image is what is maintained as opaque. And the original selection range is now transparent. Lastly, our opacity goes from 0 to 100.