Have you ever played around with the Brightness, Contrast, Transparency, and Gamma sliders in the Image Analysis window? Now have you used the slider and then wanted to return back to zero? Sure you can try to move the slider back to its original position, but there are a few quicker ways to achieve this.
There is a text box associated with each slider. You can type the value 0 and then Enter. (For Gamma the reset value would be 1.0). This is a great way to not only reset the value to zero, but also to set the value manually.
Each of the sliders has an icon associated with it. Each of these icons is actually a reset button. So if you do not like the slider setting, you can click on the icon to reset the value back to zero.