Slightly Opaque Rectable covering screen, help!

Since I updated my iPad mini to iOS 8.0.2 when reading a book within the Books app there is a slightly opaque black rectangle covering approximately seventy five percent of the screen. This happens when within the apps options the brightness is set lower than about a third of the maximum brightness and less. I personally like it set to the lowest brightness possible; so how do i fix this?

Here are some photos.