You can make the material no use SeparateTransluceny to pick a different method (will be blurry but depending on the depth behind the material). Our DOF (like most others) is a postproess and is based on the pixel depth and transluceny doesn't have it.
We might be able to fix that outputting some stipple pattern / random occluding depth but we don't have that.
We kind of have that - see DitherTemporalAA
Depth of Field do not work well when using a translucent material, even if the material has no opacity set.
Image attached as reference.
1. Open UE4
2. Place a mesh in the scene
3. Apply any Translucent Material to the Mesh
4. Add a Post Process Volume that is Unbound
5. Set the following:
Results: DOF creates a hard transition line over the Translucent Material of an object compared to a none translucent object.
Expected: Translucent materials should give the same DOF transition as none-translucent materials.
Head over to the existing Questions & Answers thread and let us know what's up.