If the natural background is not fully optimal, you can use a photo background. This photo background from Lastolite has a weight of 4.5 kg.
From Amazon
Manfrotto LL LB7621 4m Panoramic Background Cover - Black
DigiBroadcast
Lastolite Panoramic Background 4m Black
Firstcall Photographic
Lastolite Panoramic Background, 4m, Black - 7621