Because 70mm film and projectors are costly and difficult to mass produce, IMAX debuted a digital projection system in 2008. It uses two projectors that can present either 2D or 3D content in DCI or IMAX Digital Format (IDF) (which in itself is a superset of DCI). As of 2012, IDF uses 2K-resolution. The two 2K images are projected over each other to make the image brighter.