Background image scaling

I successfully loaded a background image (hosted at Dropbox) for my dashboard. I’m designing a dashboard for my new Kindle Fire HD8, whose screen is 1200x800. I made my background image the same pixel size (1200x800). However, part (maybe 15-20%) of the background image is off the screen on the Fire Tablet. Its like the image is being scaled up beyond the screen size. I’m using Tiny tiles in the dashboard config. If I change the dashboard tile size to small, the image scaling is even worse and most of the image is lost off the screen.

If anything, I’d have guessed SharpTools would have scaled the image such that it fills the device window in one direction, and letterboxes the other axis. If it did that for my image, it would fit the screen just right since they have the same shape. How does SharpTools size a background image, and why does it depend on the tile size I’ve chosen?

The background is scaled to fill the size of the dashboard, including any tiles that are offscreen. This means the background scrolls with the dashboard as you scroll the dashboard.

Ah, that makes sense. Thanks!