In Photoshop, the history brush is used to selectively revert your image back to a previous state.
There are certain adjustments that you may want to make, but not image-wide. I think of it as being like a virtual edge trimmer for your image - you do the overall cleanup of the image, and then can use the history brush to selectively fine-tune the rest of your picture.
Say you sharpen up your image and then want to go back and de-sharpen certain areas - this can be done with the history brush. Say you change the levels, curves, or saturation on your image and wish to remove the effect on certain portions of the image - this can also be done with the history brush.
The one caveat that can be frustrating about the history brush is its inability to revert back to states if the canvas/image size was different. This means that you can only go back in history in the period of time where the image stayed the same size. For example, say you have an image that was 1024x768. You apply a boost in saturation and then reduce the image size to 640x480. You cannot use the history brush to brush out this saturation in the 640x480 image.
Now I've made it sound like applying the history brush is difficult to do. In fact, it's not hard to use at all. The above was simply a forewarning for a catch-22 with the tool that we all fall susceptible to at times.
Now, let's get to using the history brush!
It almost doesn't matter what effect you apply to your image as long as you keep the same image dimensions.
For this example, I'll be using a gaussian blur on one of my images, and then will use the history brush to selectively isolate the subject (leaves) from this blurryness. This is probably better done with a quickmask or layer mask, but for the sake of demonstration I'll be using the history brush.
For starters, you need to be familiar with the two most important aspects of the history brush: how to select what history state you will be reverting to, and where the tool itself is.
First, I've applied a 3 pixel gaussian blur to my image.
Here's what that looks like:
You are going to want to anchor the history brush at the point just before the undesired effect. Click in the box next to that state (highlighted for demonstration):
Click on this tool (again, highlighted for demonstration):
Just like with any other brush, you can set the size, shape, and hardness of the brush. Brush over the section of the image that you wish to remove your effect from:
Here is the final result:
I've basically un-blurred all of the leaves in the image and the background maintains its ultra-blurryness.
Thanks for reading!
 feedback form
 feedback form
by DavisPhotog 
last modified: 2005-09-27 19:43:30 |
