A couple of weeks ago, I wrote my first real post about learning how On1 softwares presets and filters really work. In that post, I opened up a blank white .jpg and applied an Adjustable Gradient Filter. After closely looking at how the filter works on white, the next thing to do would be to open up a pure black image. I was actually kind of surprised by the results, which we'll talk about here in a second.
In the white image, we discovered that some of the preset filters (Darken, Warmer, etc) would actually put an adjustable gradient that you can sort of visualize. When we learned to manipulate that gradient, we could see how it worked. I was expecting the same thing on the black image in reverse. For example, I figured that if "Darken" would have an effect on the white test plate, than certainly "Lighten" should be able to have an opposite effect on the black test plate. That doesn't happen. If you open a black test plate, all you see is black. The Lighten Adjustable Gradient does nothing. I played around with every one of the starting points, including the Gradient Shape dropdown, and then the Overall Setting sliders and got nothing.
Thinking about this, I suppose it makes some sense. Pure black is pure black. There wouldn't be any detail in those pixels that could be lightened or adjusted, so that's probably why it doesn't work. At least that's my current theory. This is important to note when we apply this knowledge to a real photograph. If our image has a lot of deep, dark shadows, an adjustable gradient filter isn't going to work on those local areas. It will definitely have an affect globally, but those little intricate areas might not. If we want these areas to be lighter, we might have to use a Brightness or Curves adjustment layer in Photoshop to lighten the area that we want. I suppose that area could also be dodged in Photoshop as well.
Putting this into practice as I begin to use the adjustable gradients filters, I am going to be very aware of where I am placing them and the the range of highlights to shadows the filter is having an impact on. I've never really paid attention to this before. I have one more test plate to do (50% Gray). I suspect the results of that test will be much like the white one, but after doing this on black, who knows.
I'm going to try and get to the Gray test plate experiment next week, so check back then. If in the mean time, you know of a better explanation of why the black gradient doesn't seem to work, please let me know in the comments or by dropping me an email. I'd love to hear from you. More soon. Thank you for reading today.