Solemnchaos, Maybe there is an error in my drawing when I consider how it should be. What I always thought is the following : The first square plane is the beginning of the not blurred aerea, the "x" is the center of it and the second square plane the end of it. BUT... my experience shows that this is not exact when applied, as you can see at the images above. Because in this case, the tree close to the cam in the 90 focus image should be clear. And it is not. Only the centered tree is. The second image shows the same scene with a 200 focus. Only the farthest tree is clear (the one close to the "center", the "x"). Both images are rendered ULTRA, the only render mode to "see" the blur correctly. Mostly when I use blur, I only take 2% if I don't want to have bad surprises. And I always consider the not blurred part between A and B (from the previous drawing), also I will not be disappointed :-). Hope this helps. But maybe other users have a different approach to this and can tell you more (with samples images, please :-) Guitta