Question Gaussian Depth of Field always blurs Transparents

It seems like when I use the Gaussian mode in the Depth of Field post-process, it always blurs objects rendered with transparency such as particles. So basically all my particle systems are blurry even when they're positioned between the camera and the Start value. Is this just the reality of the situation or is there a way to fix this? Thanks.

 

I think the Depth of field post process effect relies on the z-buffer having data for the pixels that should be blurred. Transparent pixels is not rendered to the z-buffer and will instead be sampled by the pixels behind the transparency.

If it is okay to have no depth of field on the particle system you could render them using a second camera that has disabled post processing and stack it on top of your base camera.

 

I appreciate the explanation. It makes sense now. Thanks.