It sounds like you’re referring to the IMAX 15/70 mm film prints of The Dark Knight and The Dark Knight Rises—specifically, a portable or homemade projection setup (1431 might be a typo or model number? Possibly a lens, reel, or DIY IMAX projector reference).

Optimized Devices: These "portable" files are specifically intended for screens with taller aspect ratios, such as iPads, MacBooks, VR headsets, or specialized projectors. The Dark Knight The Dark Knight Rises IMAX, 35mm, The Dark Knight Rises, and you - Flixist

IMAX Experience