In this example, the ItemPathStretch is changed to Uniform from its default value of Fill so that the aspect ratio of the path is preserved.
<igWindows:XamCarouselPanel>
<igWindows:XamCarouselPanel.ViewSettings>
<igWindows:CarouselViewSettings
ItemPathStretch="Uniform"
ItemPathRenderBrush="#77000000" />
</igWindows:XamCarouselPanel.ViewSettings>
</igWindows:XamCarouselPanel>