How do they make old movies look good?

I've recently rewatched 12 Angry Men, one of my all-time favorites, and this question popped up in my head again. How do they make old movies look good? The facial details, the creases on shirts, buttons - these all seem like something that would not be captured by the cameras of the day, so I assume that mainly digital reconstruction on a frame-by-frame basis is used.

Then again, after watching The Cabinet of Dr. Caligari, which is a silent 1920 German film (and holds up surprisingly well, by the way), I remember reading something about them having to get access to the original reels to remaster it. So it's also a matter of properly 'deciphering' the old reels themselves?

Freaking movies, how do they work?

Film - real analog film - has essentially infinite resolution. You can "up-res" that shit for days. Provided the cameras were in focus - and for something like 12 Angry Men which was a fairly big budget production in its time, they were likely in focus. With the original reels, you wouldn't have any degradation that would come from copying analog to analog. You could get some really high quality scans.

Copy degradation is an interesting subject. If you're interesting in it as a concept, listen to Alvin Lucier's "I am Sitting in a Room", or watch this cool YouTube tribute/remake:

Film cameras can capture amazing beauty. However it was not possible to get that quality on a home format, because of home standards of the time. Film really has no "resolution", no pixels. TVs have a resolution, they have pixels. Film cameras capture light and throw whatever image the camera is pointed at directly onto the film. The standard for film is 35mm, that standard was capable of being projected on a 40 foot screen with out being converted to any other format. Meaning that the film lost very little information between shooting and displaying.

Now when talking about viewing those films at home, which I assume thats where you've primarily have seen these old films. You really have to talk about formats and standards of the time.

When home video really took off the Standard TV resolution was 720X480 amazingly small compared to a film that when projected would encompass a 40 foot screen. When putting a Film negative on a VHS in the 80's you'd take the film and digitize it, significantly lowering the quality. To get a film that was meant to be shown in a wide screen format (close to todays 16X9) to show on a TV you'd have to squish, squeeze, and pan/scan it to fit the standard square 4X3 format. The VHS and the DVD format are not capable of holding all the information that a film had. Simply put there was not enough space on VHS and DVD to display the movie in the quality that the original film would have. So technicians of the day would have to sacrifice image and sound quality to get these films on to a home format.

Now that blu-ray exists and the standard for home TV is 16X9, and the technology has evolved far enough, technicians have been able to go back to old films and rescan them from the original film negatives in a 2K to 4K resolution getting most of the original information that was shot. When doing this the technicians may fix things that have going wrong with the film over time. If a film is stored properly it can last for centuries; however, if its stored badly film becomes susceptible to many problems. Films just now in the last 10-15 years are being able to be shown in the home close to the way that most people would have seen them in the theatres.

If you are more interested in digital restoration and the process behind it. track down the Criterion copy of "The Red Shoes." it has a interesting documentary with Martin Scorsese about the restoration that the film underwent.

I seem to remember reading at some point that we have already been able to get an 8k equivalent resolution out of 50+ year old 35mm film and that the only real issue with the picture of regular film comes when you blow it up too large because of the film grain effect you get.

@murick: Great informative post there. I always figured that there would be some resolution threshold for film, but the idea that analog film is not beholden to the limits of resolution is pretty mindblowing.

@sinusoidal: @murick: Thanks, that clarifies a lot!

I'd kinda thought that traditional reels, while receiving light in an analog way, had a limited 'maximum resolution' that was an effect of the material itself having a somewhat grainy structure (the 'pixels' of the material) with the grain size decreasing and therefore resolution increasing as technology progressed (up until the digital era). I wouldn't have suspected the degree to which you could extract detail even from an almost century old analog reel. That's pretty cool.

I really love the look of old black and white films on blu ray, especially if they're transferred right. Im guessing you're watching the criterion version of 12 angry men? They do really fantastic transfers.

@imsh_pl: celluloid is not technology based, it's chemistry, silver halide particles reacting to light, hence the need for darkrooms and all that, but a piece of 35mm celluloid from eighty years ago is basically the same as one made today, different film stocks do have very different characteristics, that's why 70s movies look like 70s movies, it's the particular stock that Kodak and Fuji were promoting at the time, but it's the same process now as then, and the same amount of grain, you can't change that, it's those little halide critters, you get more noticable grain in 16mm because it's half the size, projected to the same proportions, and with 70mm it's much less noticeable. Also, if you use insufficient light for your shot, and rely on the film stock to compensate for an exposure, the grain becomes more noticeable, and if you use tons of light, and can close your aperture right down as a result, it's less noticeable. But they knew all these tricks way back then.

technology arrived late in the game, and took hold because video is cheaper and easier to manage, but only now is it catching up to what celluloid film can do.

I've worked in a film lab as a digital restorer and like people said you can basically scan film at an infinite resolution. The digital scanners of today will make for a very steady picture (instead of the old telecines where the film wobbled in the gate). They'll digitally color grade it to get the most out of the material, but still keep the old color timings intact.
Then it's off to the digital restorer to paint out the biggest dust specks and hairs. Pretty tedious work, but the results are great: a steady and clean picture from old material.

I remember reading that 35mm film is "equivalent" to 4K video, in that any higher digital resolution is negotiable to the human eye. Wish I could remember the source but I think it had to do with film grain.