For those of you who like to be scared, Ecran Total published
an interview (in French) with Guillaume Schiffman. He is a French DoP (and worked notably with Michel Hazanavicius) and has supervised the Wages of Fear 4K restoration.
In introduction, remember he worked on the Marseille Trilogy restorations (and also the French MK2 restoration of The Last Metro).
Selected abstracts :
"I worked on The Last Metro restoration, my mom wrote the scenario. I always admired Almendros' worked, he was kind of my mentor in the profession. I tried to pay his work a hommage by improving it without betraying it."
"When I work on a frame, I put myself in the DoP place and tell myself that if he could have improved this or that aspect of the picture, he'd done it."
"We started with a 4K scan of the OCN, but many sequences looked like they were from an IP scan, with a lower quality. To avoid making the change of quality obvious, we had to "degrade" progessively the picture before the cut, and then "improve" it after."
"I had to correct some day-for-night shots or to improve some backgrounds behind the trucks windows which were performed in studio and which would look quite dated today."
"For the sequence where Charles Vanel falls in the fuel, we had to unify the blacks and to add brillance on the fuel to reinforce the effect."