zdepth RE without filtering does not represent transparency

[leabum]

Obviousely filtering has to be turned off in the zdepth RE when it is intended to be used for DOF to prevent artifacts around edges, but in my case where I have a very fine opacity cutout on the flags in the scene, the desired transparency which is also ment to be present in the DOF does not get rendered as needed. In the attached image you can see the unfiltered version in the red box vs. the filtered version on the outside of the box. What is the correct workflow for cases like this? Rendering the flags in their own layer with filtered Zdepth maybe?

[Svetlozar Draganov]

You may extract multimatte mask for the flags from the first render pass and then use those as render mask to render a second pass with filtering on.
It would be better to check if the filtered z-depth element is useful for the compositing stage, if it is not there is no point to render a filtered version of the z-depth element.