Filmmakers have relied on film to make their movies for almost as long as the industry's been around.
Digital projection does not degrade the quality of the picture
Shooting on film may be expensive, but it has a special quality unrivalled by any other media, and though we are not necessarily aware of what is going on behind the scenes when we turn up at the box office, we are stepping into the world of 35mm film.
The release prints of movies arrive in projection rooms as 10,000 feet of film printed as a copy of the original.
So far the only sop towards digital in the analogue cinema world has been in the realm of sound.
But now, finally, film itself may be facing the final curtain as cinemas find the pull of digital forces irresistible.
Digital projection systems are the latest thing. The release copy of the movie is delivered on a hard drive, sporting 100 gigabytes of the latest Hollywood fare, a digitally scanned copy of the master film print.
The industry has reached a watershed, and digital cinema is about to take off in a big way
Once clipped into place the movie is simply uploaded to a server and is one button-push away from being digitally projected.
The big advantage of digital projection is the picture quality. With film, every imperfection gets shown as the 35 mm print passes through the projector, including scratches, fluff, blotches and so forth; not exactly what the director intended for their creative vision.
With a digital projector linked to a server there are no more stray hairs, scratches or dust - just a crystal clear picture.
Goblet of Fire from Warner was released digitally in 18 countries
The rest of the entertainment world embraced digital years ago, so why are the cinemas so late to the party?
"It's taken so long because it's been a question of agreeing in advance," said David Hancock of Screen Digest. "It's been a consensus building process, which started in 1999 with the first commercial release of Star Wars Episode One.
"Since then we've had five years of testing the technology, building a consensus and agreeing the business models and technology to be used, and this took longer than most people expected."
Now the industry has reached a watershed, and digital cinema is about to take off in a big way.
A couple of years ago there were only 335 digitally-equipped screens worldwide. By the end of last year, in which Hollywood finally published a common technical standard, that number had almost trebled, to 849 screens.
Forecasts predict 17,000 screens in just a few years from now, concentrated in the movie world's spiritual home, the US.
Digital encryption will help protect against film piracy
The Hollywood studios are driving this transition because they stand to make enormous savings, which they can pass on to the cinemas themselves.
The most obvious saving is in distribution costs. An average length feature film print costs around £700 ($1,300).
Encoding it and delivering a hard drive to the cinema works out at a fraction of that. In future, the possibility of delivering the movie by satellite or over the net has got the bean counters salivating.
One of the other great costs to the movie industry is piracy, which Hollywood claims has cost it $6bn (£3.2bn).
Distributing movies digitally means they can be encrypted before they even leave the studios, and then unlocked by software at the cinemas themselves.
Tinseltown's films could get more showings, too. Digital movies can be streamed from the server to different screens at the same time; or alternatively a variety of movies can be shown on the same screen throughout the course of a day.
But perhaps the most exciting thing for the cinemas is that digital projection gives them a flexibility they could only have dreamt when they had to use film.
"With a digital projector you can input virtually anything into it," said Steve Knibbs of Vue cinemas. "[We can screen] a DVD, a clip downloaded from YouTube, gaming from a digital projector with multiple players on the screen at the same time, a live feed from satellite, cable and whatever.
"Anything we can get as an input we can put up on screen. That means we go from being a place where you can just see 35mm films to becoming a true general entertainment place providing everything from gambling to gaming, educational lessons to movies they might not have seen for 40 years, and all sort of things like that."
'Buzz about 3D'
The advent of digital also means that some technologies which were a bit suspect in the past can be revived. Brace yourselves for the return of 3D.
In truth 3D never really went away - it has been the staple of the big-screen Imax experience for years.
Imax uses two film projectors and two reels of film to fool our brains into thinking we are seeing 3D.
That process has been too expensive for regular cinemas to contemplate, but digital projectors make it affordable for the first time.
"It's not proved financially viable for some time," said Richard Boyd of the National Film Theatre.
"This was something that was quite big in 50s and 60s and sort of dropped out, a bit of a gimmick, a bit like smellavision.
"But now a single digital projector can run at a higher frame rate and show both left eye and right eye [images] from a single projector."
There is now a real buzz about 3D; there are seven new 3D movies slated for release in the coming year.
With technology available to recreate old classics, as well as show sporting events, in 3D there is a real feeling that 3D is finally coming of age.
Even so, places like the Hollywood entertainment museum put these developments in perspective. Technology is important, but it is just one part of a bigger picture.
Digital cinema, although it is being seen as a milestone on par with colour and sound, is still at its heart just cinema.
Ultimately it is the finished product, the movies themselves, which will ensure we keep coming back for more.