Radial Blend filter blurs an image and blends the result with the original. Thus you can add only subtle radial accent to your image instead of full radial blur. Parameters: Blur Type "Constant" mode represents the real spin/zoom blur effect while "Soft" adds subtle directional blur. One-Way variations add not only blur, but a visual motion also. Size Controls the blur power. Value of 1.0 set 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. Distribution Controls the blur distribution over the image. Higher values limit the blur's power in the center. Direction Controls the blur direction. Value of 0.125 - spiral, 0.25 - spin blur. Center Controls the position of the blur center point. By keyframing the Center control, you can have the effect's center track your subject's movement. 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 Radial 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. Blending modes allow you to blur only a specific channel, to get light rays and many other effects. 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 Radial Blur variations: Radial Blur - Radial, spiral and spin blur.