The Mamiya RB67 is a medium format twin-lens reflex (TLR) camera produced by Mamiya from 1970 to 1986. Its unique design features two lenses, one for viewing and another that actually captures the image, allowing photographers to compose shots without the need for a viewfinder or separate lens. This innovative design made it a popular choice among landscape, still life, and portrait photographers seeking high-quality images with shallow depth of field capabilities.