Are soft edge drop shadows possible? (as in the docs)

[A Former User]

Update: Ok, poking around for a while, it appears that the "transparentBorder" property needs to be set to true in order to get soft edges. Didn't see this mentioned in the docs.

       DropShadow {
            anchors.fill: rect
            horizontalOffset: 20
            verticalOffset: 20
            radius: 16
            cached: true
            transparentBorder: true // <----------- TRUE
            fast: true
            samples: 16
            spread: 0
            color: "#80000000"
            source: image
        }

Original Issue
I've been unable to get a soft edge drop shadow on an image no matter what settings I try. The docs indicate that this is possibe by adjusting the DropShadow - Radius property but it's not working. I get the following result with the code below:

Am I doing something wrong or is this a bug/known issue?

    Rectangle {
        id:rect
        width: 320
        height: 240
        color: "blue"

        Image {
            id: image
            anchors.fill: parent
            source: "qrc:/images/image1.png"
        }

        DropShadow {
            anchors.fill: rect
            horizontalOffset: 10
            verticalOffset: 20
            radius: 8.0
            samples: 16
            spread: .2
            color: "#000000"
            source: image
        }
    }