sfdex, Just like GI settings, it requires a little finessing and intelligent use of settings. Heap on a bunch of effects or max out certain settings and your computer system will be gasping for air. It does essentially "scrub" the time line so here is how I estimate rendertime so I can adjust my settings well: I render the image without blur and check the time. Next, you can set how many frames you want rendered to create the effect. I'll start with 10. You can also have the blur occur in front, behind or in both directions. If I choose "both" it will render 10 frames in front and 10 frames behind plus the original frame for a total of 21. Then I just do the math and make adjustments as required. Mark