Mike Rundle: “The main light source comes from the top but that doesn’t mean you can’t introduce a secondary light source for emphasis. Below I’ve created a custom navigation bar for an iPhone application that uses a subtle radial highlight for added dimension and detail. The Blend Mode has been set to Overlay to brighten and saturate the overall color and the transparency has been knocked way down to keep it realistic. Also note the edge highlights to make it look more like a raised surface.”
Mike is the author of Design then Code.