The missing "Lens Blur" effect in After Effects isn't actually a bug, but rather an evolution of the software. Years ago, Adobe officially replaced the original Lens Blur plugin with the more powerful Camera Lens Blur.
Project Settings > 16 bpc.Fast Box Blur + Levels (Gamma down).Composition Settings > 3D Renderer > Cinema 4D > Enable DOF.Gaussian Blur (ignore the bokeh, just blur).First, a hard truth: After Effects does not have a stock effect natively named "Lens Blur." lens blur after effects missing free
The original "Lens Blur" was phased out starting with After Effects CC 2017. The missing "Lens Blur" effect in After Effects
Effects menu at the top of the screen.Effect > Blur & Sharpen > Obsolete > Camera Lens Blur.