# Transparent BSDF cause noise in depth layer

I have system that consumes depth and RGB output of Cycles renderer. I can observe noise in depth maps when I use transparent BSDF with Mix shader and RGBA texture. Let's look at sample simple shader:

That shader is giving material that is transparent with level of transparency given by alpha channel of texture. I am not happy with depth image, especially on edges (white dots):

Two factor has to be present to "depth" noise appears:

• There must be some other object behind the part that is transparent.
• The noise seems to be absent when alpha channel has only value 255 or 0.

A this moment I found some solutions:

• using mist pass
• using material override

First solution seems to give depth values in some bizzare scale (I need it linear in meters, like Z-pass) and the noise is still present. Second solution is not acceptable, because removes desired feature.