Great observation and thank you for the explanation, I was encoutering the same issue! This definitely seems to produce a correct Laplacian. A follow up problem I have when using the x2 gaussian:1. Generate the Gaussian as described above: looks ok other than brighter mip map levels2. Generate Laplacian pyramid from the above gaussian: looks ok3. Collapse the above laplacian using MPSImageLaplacianAdd: this is the one causing issues! Ideally you should get the original gaussian at level 0 which is it does ONLY if the image size is smaller than a certain dimension! For bigger images I am getting black rendering. Is anyone able to reproduce this? This does NOT happen when using normal MPSImageGaussianPyramid without x2 weights (but then the laplacian pyramid is useless)! The other question I had was: has anyone played with the laplacianBias and laplacianScale parameters available with MPSImageLaplacianPyramid ?