Optical nondestructive readout of photographic film allows the forensic photographer to see image detail despite overexposure, underexposure, or both. The methods involve direct schlieren viewing of the surface relief image of the original negative. A "super camera" largely insensitive to range and brightness variations in the scene is described.
H. J. Caulfield,
"Image Dynamic Range Compression For Law Enforcement", Proc. SPIE 0339, Optics and Images in Law Enforcement II, (23 June 1983); doi: 10.1117/12.933651; https://doi.org/10.1117/12.933651