One thing to consider when comparing resolution is the size of the screen and how far away you are from it. A 1080p resolution Blu-Ray disc shown on a 40-inch screen will appear much more pixelated than on a smaller twenty inch screen. The same principle also applies with film.
The most common resolution for Blu-Ray discs is 1080p, which means it has 1080 pixels along the horizontal edge of the screen. Film does not contain pixels,and instead captures images using tiny silver halide crystals. After being subjected to various tests, experts have speculated that film can contain up to 12 million pixels, an obvious advantage over 1080p’s 2 million.
Consider is that the human eye can only take in so many details. Although film tends to have a much higher resolution than Blu-Ray discs, as HD image quality improves, our eyes will not be able to tell the difference between a high resolution digital transfer and 35mm film.
35mm film is converted for use on Blu-Ray discs using a process called ‘telecine.’ This involves scanning a print of the film at very high resolutions. Many studio films are scanned at 4K resolution (about 4,000 horizontal pixels) and downconverted in order to fit on the Blu-Ray disc.
For home use, there really is no better format than Blu-Ray, as far as image resolution is concerned. Any resolution higher than Blu-Ray will likely be indiscernible in a home viewing environment.