Note how effectively the High-Pass layer can restore detail to the blurred layer underneath, when used in the modes previously mentioned. All of these are at 100% opacity. If you turn off the blurred layer, so that the High-pass layer is blending into the original image, you will see how the filter can be used as a sharpening method. It's effective, but not nearly as effective as it will be once you understand what is really happening and can exploit the effect to its fullest potential.

Note how effectively the High-Pass layer can restore detail to the blurred layer underneath, when used in the modes previously mentioned. All of these are at 100% opacity. If you turn off the blurred layer, so that the High-pass layer is blending into the original image, you will see how the filter can be used as a sharpening method. It's effective, but not nearly as effective as it will be once you understand what is really happening and can exploit the effect to its fullest potential.