This is not another sky dome or set of background pictures.
This is full 360 degrees spherical environment! This is modified
'Skybox' and it allows you full all around, above and below renders.
With matching light sets, powered with HDR IBL, you can set great
scenes in few minutes, and make unlimited renders from different
angles just by moving camera around your scene. Special FOV 3000x3000
seamless textures allow even great animations.
This is all great illusion of standing in center of large sphere.