Here's a quick lens flare test with a Proskar 2X lens and four diopters attached. I stacked a Tokina achromatic +0.4 doublet and a Hoya close-up lens set (+1, +2, +4) on the Proskar. My taking lens was a Pentax Auto Takumar 55mm f1.8 lens. Panasonic GH2.
http://vimeo.com/77529401