I don't think there is. The issue is that the depth field needs to be pre-calculated so that a blur shader can control the level of blur based on the depth field. In DBPro a depth field tends to be an extra camera in a clone of the level geometry, coloured white with a black fog, so the brighter the pixel, the less blurring is applied. All this legwork is complicated and takes a real hit on performance. The extra camera, the extra render, the extra scene, then a variable range blur makes a big dent in your frame rate.
I would be tempted to control blurring on an individual object instead, based on it's distance to the camera - maybe even just hijacking the objects colour to control this, like use the red component to set the distance in code, then in the shader you could use that to control the blurring range of the texture. Would work nicely with flat plains and transparent textures, like foliage for example, but actual geometry might just look daft... you'd still have sharp edges on geometry. Really I think that if your project relies on a big terrain or lots of geometry with a long view range, then depth of field is not a good idea, it takes too much performance for what it gives. Depth of field works better for DBPro with stylistic games, like those short, minimalist, spooky adventure games that we saw a few years ago here.
