Like Coppola, I too am a huge proponent of digital filmmaking, having filmed feature length films in formats ranging from true native 4K to 1080p on the latest crop of DSLR cameras from Canon. However, the most interesting conversation to take place over my brief stay at the Rubicon Estate was not about digital versus film but about how home theater projectors have gotten so good that they've begun to blur the lines that once separated your living room from your local theater. It's true. Don't take my word for it - Francis Ford Coppola uses a SIM2 home theater projector in his postproduction suites when coloring and mastering his films.
Now, I'm not going to sit here and say that Mr. Coppola and I are in the same league, hell we're don't even play in the same stadium. However I've been a firm believer and supporter of using high end home theater equipment in professional applications for some time now and it's always nice when one's point of view can be given a bit of credence by someone as influential as Francis Ford Coppola. I've mastered two films, one at the 4K/2K level and the other at 1080p, both on high-end home theater projectors and the results have been nothing short of astonishing. Aside from the obvious cost benefits, a true digital cinema projector from the likes of Sony or Christie can cost upwards of $100,000 whereas a quality home theater projector can be had for anywhere between $10-20,000. The differences between the pro world and the consumer world are not that far off.
When it comes to editing a film, oftentimes the filmmaker is working with a low-resolution image in order to maximize software and processing speed. These video files can range in resolution from 480i to 1080p depending on the system and/or postproduction supervisor. Needless to say one does not require a high end or professional digital cinema projector during the editorial phase of post production, often your run of the mill computer monitor or a medium to large size LCD HDTV will suffice. However, once a film is out of editorial it is often up-resed to the final output resolution or at the very least up-resed to a comparable size that can later be proxied to the final output. For example when working on my first film, which was shot in raw 4K on a Dalsa Origin II camera system, editorial was handled at the 480p level, then later up-resed to 1080p for coloring. Since we knew the final product was going to be projected in 2K we were able to color the film in 1080p, which saved us time, money and processing power before applying the 1080p color files or luts to the 2K and 4K footage. While 2K is a higher pixel resolution than 1080p, in terms of color they react to commands and input from the colorist much in the same way - provided your 1080p footage hasn't been to heavily compressed or compromised. Because we were able to keep the entire postproduction workflow in the consumer HD realm we were able to utilize higher end consumer grade projectors like the ones made by SIM2 and the like, versus having to pay the rental prices on an expensive Sony CineAlta or Christie Digital projector.
In a direct A/B comparison between the color corrected 1080p master and the projected 2K image on a 200-inch Stewart cinema screen, the images were virtually identical. When comparing the 1080p master files to the color corrected 4K files on the same Stewart screen there were differences in detail but not in color, which is what you care about most when color correcting a feature film. I later found out that Quantel, makers of the phenomenal Pablo postproduction compositing and coloring suite that costs upwards of $500,000, use JVC DILA 1080p projectors with their systems. If Francis Ford Coppola wasn't enough of an endorsement, the Quantel Pablo system was used exclusively to put the finishing touches on James Cameron's "Avatar."
There's no denying the fact that 2K and 4K are of a higher resolution than 1080p. They're even a higher bit rate, at least when dealing with raw 4K files from the now defunct Dalsa Origin II system. However if filmed correctly, the differences between 1080p and even 4K in terms of overall color fidelity are not going to be night and day. Die-hard home theater enthusiasts and videophiles have been hip to the notion that their home theaters rival, if not surpass, the experience of going to the movies on a Friday night - and it would seem Hollywood is beginning to agree.