Linear (Motion) Blend filter blurs an image in one direction and blends the result with the original. Thus you can add only subtle linear accent to your image instead of full motion blur. Blending modes allow you to blur only a specific channel, to get wind and many other effects. Parameters: Blur Type "Constant" mode represents the real motion blur effect while "Soft" adds subtle directional blur. One-Way variations add not only motion blur, but a visual motion also. Size Controls the blur power. Value of 1.0 sets the maximum blur, but you can enter in edit field values from -4.0 to 4.0 and get more blur, but with a slightly reduced quality. Negative values set opposite-direction blur for One-Way modes. Direction Controls the blur direction. Value of 1.0 = one full rotation (360 degrees). You can enter values up to 100.0 and create direction animations (rotating direction). Blend Mode Select blend mode. Almost all known blending modes are realized here. Opacity Controls the blend opacity. Value of 0.0 is equal to 0% opacity (base image) 1.0 is equal to 100% opacity (blended image). But while most effects stop here in Linear Blend you can get mix between blended and blurred image (values in range 1.0-2.0). Plus - you can enter in edit field values from -20.0 to 20.0 and get other unusial effects. The power of color blending modes - you can blur/offset only the colors or some color channel.  With some blending modes or by entering in opacity edit field values out of 0.0-2.0 range you get new, sometimes very unusual effects. See also Linear Blur variations: Linear - Blur an image in one direction. Variable size - control the blur power within the frame with a Radial Mask, or Linear Mask.