CC summed it up really nice and simple. I wanted to jump in and just say what is happening without being too techy when using a high-pass filter and many other features in PS. PS does not see or interpret colors as our eyes do, the program places a value on a color 0-255, black being 0 and white being 255. This is important to know because this is per pixel in the image and the high-pass filter allows for a threshold of surrounding pixels. Adjust the threshold too high, and the halos will appear and the image may be over-sharpened, too low and it may not choose enough of the surrounding pixels to properly sharpen the image. Try this for an example, it may be a better visualization for what the color values are and how PS interprets it. RGB Color Value Codes
The reason I bring this up, is if you have an image that has very little contrast and is a little on the blown out side, high-pass filtering may not work as intended.
It’s always good to know a little bit of what magic PS is doing and how.