6/29/2019

How Film Restoration Works by Chris Opfer from Howstuffworks

How Film Restoration Works by Chris Opfer from Howstuffworks

Some movies shouldn't be revisited. Johnny Depp fans and other poor, unfortunate souls who sat through "Mortdecai" will never get those 107 minutes of their lives back. The best thing they can do is embark on a Paul Revere-esque mission to warn the moviegoing masses off from the depraved beast marching through their towns from theater to theater. Sure, there are certain flicks that are so bad that some might actually get a kick out of them. Why else would so many frat bros still have "Boondock Saints" posters tacked up on their dorm room walls?

On the other end of the spectrum are films that advance the art form and tell the story of the world in which we live. These are the "Citizen Kanes," the "Casablancas," the "Godfathers" and the "Graduates" of the film industry. When aliens descend on what's left of planet Earth thousands of years from now, these are the movies that we should want them to find. That's not to mention a whole slew of flicks that are worth hanging on to because they inform us about the world, are entertaining or are just plain fun. I don't know about you, but I certainly wouldn't have realized that there's no basement in the Alamo if it wasn't for "Pee Wee's Big Adventure."

Unfortunately, many films have been left by the wayside over the passage of time. According to the U.S. Library of Congress, less than 20 percent of American feature films from the silent era remain intact. Meanwhile, half of the movies produced in the U.S. before 1950 have already been lost.

The good news is that researchers and film buffs are working to restore and preserve the movies that we still have.



Film vs. Digital

Until a couple decades ago, moving images were captured exclusively using photochemical film. You know, the stuff that comes in those big reels and that you have to hand-feed through a projector to get on the big screen. These days, however, more filmmakers are turning digital production techniques to shoot and screen their pictures. While the differences in the final product may be subtle to the untrained eye, the two techniques vary widely.

The film used to capture moving picture images has two components: A light-sensitive emulsion and a plastic base. Here's how Kodak explains it:
An easy way to think of film is to compare it with bread and butter. Think of the bread as the base, the butter as the emulsion. When you hold this combination in your hand, what you feel and see is mostly bread, the base -- not butter, the emulsion. The base (bread) holds and supports the emulsion (butter), the active part of the film.

The emulsion is a type of gelatin composed of silver halide crystals. A camera records images by transferring photons of light onto the film as it rotates behind the lens. The crystals turn into silver metal when exposed to the light and form a photo image during the film development process. The series of photos captured on the film can be seen individually once it's developed and create a moving picture when the film is run through a projector [sources: Kodak, Side by Side].

Digital recording, on the other hand, uses an electronic sensor to capture an image, rather than a chemical process. The light that travels through the camera hits the sensor's pixels, creating a number of individual electronic charges that together create an image. The images are stored as data, which can be transmitted via discs, flash drives and the like [sources: JISC Digital Media, Side by Side].

The film vs. digital debate is currently raging on just about every movie studio lot from New York to LA. Film purists often say that they like the gritty, granular feel that comes with the old-fashioned method. Academy Award-winning cinematographer Wally Pfsiter called switching from film to digital "trading oil paints for a set of crayons." Those who have embraced the technology, meanwhile, tout the immediacy of the process. Instead of shooting a scene and waiting to see what it looks like once the film is developed, directors and actors can see what they have right away. Director Robert Rodriguez has compared digital to film by calling the latter technique "painting with the lights off" [sources: JISC Digital Media, Side by Side].
Size Matters

Cinematographers typically use four different types of film – 65 mm, 35 mm, 16 mm and Super 8. The names refer to the films' "gauge," or width in millimeters. Thirty-five mm is the most commonly used type of film for movies because the size of the photos transfers most easily to the big screen. Sixteen mm is used primarily for lower-budget pictures that are later blown up to 35 mm and for TV. Images shot on 65 mm are usually printed on 70 mm film to get the widescreen feel used in IMAX movies. Cinematographers often turn to Super 8 (8 mm) for a vintage, old, home-movie feel [source: Kodak].



How Film Deteriorates

While the choice between digital film moviemaking may be one of personal preference, what we do know for sure is that film reels have a much higher risk of being damaged or destroyed over time than their video counterparts.

As the plastic and emulsions age and are exposed to elements like light and temperature, colors fade and images may denigrate. The culprit is often something called nitrate deterioration. Until the early 1950s, most American movies were recorded on cellulose nitrate film. When the nitrate deteriorates, film often shrinks and begins to give off various acids that separate the emulsion from the base, yellow the individual still photos and make the film so brittle that it eventually crumbles and turns into dust. High temperatures and humidity can speed this process. While the acetate film versions that followed are also subject to decay, modern polyester film is believed to have a shelf life of hundreds of years [sources: Library of Congress, Kodak].

It's not necessarily the Hollywood classics at risk of being destroyed because many of these films have already been restored and transferred to digital formats. Instead, it's the lesser known independent and avant-garde works, along with old newsreels, documentaries and silent era flicks that have been scattered across the country over the years. Experts say these "orphan films," which were outside the scope of previous restoration and preservation projects, are important because they provide insight into what life was like in the days they were shot and recorded [source: National Film Preservation Foundation].


Restoring Film


The actual restoration work is a treasure hunt of sorts in which film archivists go searching for the early versions of the film that they want to bring back to life. The goal is to create what's called a "pre-print" copy of the original film: a master copy of the film as it once was [sources: UCLA, The Picture Show Man].

That means first locating the cleanest copy of the film that's still available. Under ideal circumstances, that would be the original negative version. That's the film that was actually reeled through the camera and used to capture the images. It's called a negative because the original film captures the image in a backward form that includes only shades of the true colors. It's later used to create a "positive" version that ends up on the screen. You need a negative to make a positive print and a positive to make a negative print. Every duplication means a loss of quality.

For many films, there are various trial, correction and distribution copies that may be floating around and could be used for restoration. More obscure pictures – those with just one or a few copies – are often more difficult to restore because there are simply fewer versions of the film from which to choose. On the other hand, more popular films raise their own hurdles to restoration because of the wear and tear endured by the negative as a result of heavy copying.

Once the various versions of the film are located, the restorer may physically cut and paste them to create a full-length master. Wearing white gloves, he'll open the film can and gently wipe off any mold. Then he'll unwind the film slowly, flattening out any curl. Using special equipment and splicing tape or film cement, he'll join pieces of film together as needed. He'll also repair any broken sprocket holes [sources: NFPF]. The idea is to remove wear and tear so that viewers can enjoy the film in its original form rather than an enhanced version.

For a big-budget movie restoration, the film may go through a device called a wetgate scanner – a scanner that runs the film through a chemical bath that fills in any scratches on the negative. Then the film is converted to a digital image. High-end graphic and editing computers can adjust the pixels so faded color becomes rich; they can also remove damaged frames of film or scratches and dirt on individual frames. This is painstaking work. It may take three or four hours to fix one frame [source: Popular Mechanics].

The audio track may also be enhanced. In the case of the "Jaws" restoration, the mono track was upgraded to include two additional rear speakers, creating a surround sound atmosphere for home viewers [source: Popular Mechanics].

And one last thing after the restoration project is complete: Another negative is created so the film will be properly preserved for posterity.
Author's Note: How Film Restoration Works

Everything I know about film, I owe to Keanu Reeves. That's right: Mr. Whoa. Dude. Bro. Yes, Reeves has left an indelible mark on the history of cinema with roles like the stoned space cadet who travels through time to visit other civilizations and ace his history project in "Bill and Ted's Excellent Adventure," an older, jock version of the same guy in "Point Break" and an older, hacker version of the same guy in the "Matrix" trilogy. But I'm referring to "Side By Side," the 2012 documentary Reeves produced and narrated about the move away from film moviemaking and the artists on each side of the film-digital debate. This is the type of flick that humble-braggers who like movies would label for "film nerds." They are wrong: I enjoyed it, and I'm one of the coolest people whom I know.
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Sources

    JISC Digital Media. "Introduction to Digital Video." (Jan. 24, 2015) http://www.jiscdigitalmedia.ac.uk/guide/introduction-to-digital-video#v08
    Kodak. "Film Types and Formats." (Jan. 24, 2015) http://motion.kodak.com/motion/uploadedFiles/US_plugins_acrobat_en_motion_newsletters_filmEss_05_Film_Types_and_Formats.pdf
    Kodak. "Understanding Film....The Basics." (Jan. 24, 2015) http://www.kodak.com/global/en/consumer/education/lessonPlans/lessonPlan152.shtml
    Library of Congress. "Preservation Research." (Jan. 23, 2015) http://www.loc.gov/programs/national-film-preservation-board/preservation-research
    Library of Congress. "Preservation Plan." (Jan. 24, 2015) http://www.loc.gov/programs/national-film-preservation-board/preservation-research/film-preservation-plan/
    National Film Preservation Foundation. "Why the NFPF was Created." (Jan. 24, 2014) http://www.filmpreservation.org/about/why-the-nfpf-was-created
    "Side By Side." Directed by Chris Kenneally. Company Films, 2012 (Jan. 24, 2015)
    The Picture Show Man. "Restoration and Preservation." (Jan. 24, 2015) http://www.pictureshowman.com/articles_restprev_negsprints.cfm
    UCLA Film & Television Archive. "About Restoration." (Jan. 24, 2015) https://www.cinema.ucla.edu/restoration/about-restoration
    UCLA Film & Television Archive. "An Interview with Bob Gitt (2006)." (Jan. 24, 2015) https://www.cinema.ucla.edu/restoration/interview-bob-gitt-2006
    UCLA Film & Television Archive. "UCLA Film & Television Archive on Turner Classic Movies." (Jan. 24, 2015) https://www.cinema.ucla.edu/restoration/ucla-film-television-archive-turner-classic-movies

Source: https://entertainment.howstuffworks.com/film-restoration.htm

6/22/2019

CDs are still better than vinyl

Happy Record Store Day! There are plenty of business-related grievances to be filed against the annual vinyl celebration, but it's hard to argue with the spirit of a day encouraging people to explore and buy new music. Moreover, vinyl's just more fun as a format than MP3s or CDs; there's something viscerally satisfying about dropping the needle, and physically spinning the record back to rewind. And in a world where people feel all too welcome to hijack the playlist at parties they attend, it's nice to have a harder-to-commandeer format on offer.

Let's not fool ourselves, though. Vinyl is great, but the idea that its sound quality is superior to that of uncompressed digital recordings is preposterous. They sound different, and that's exactly the point.

What vinyl can't do

On a theoretical level, there's just no reason it should be the case that vinyl sounds better. There are built-in problems with using vinyl as a data encoding mechanisms that have no CD equivalent. Vinyl is physically limited by the fact that records have to be capable of being played without skipping or causing distortion. That both limits the dynamic range — the difference between the loudest and softest note — and the range of pitches (or "frequencies") you can hear.

If notes get too low in pitch, that means less audio can fit in a given amount of vinyl. If notes are too high, the stylus has difficulty tracking them, causing distortion. So engineers mastering for vinyl often cut back on extreme high or low ends, using a variety of methods, all of which alter the music.

For example, one common cause of high pitches in recordings is "sibilance," or the hiss-y sound produced by pronouncing certain consonants, notably "s" or "z"s, in a quick, sharp way (ex.: "zip," "shack," "sap"). This creates enough problems for engineers working in vinyl that they often have to "de-ess" recordings, either by making the pronunciation less sibilant through editing or by straight-up asking vocalists to pronounce lyrics differently.

De-essing is a common technique outside vinyl too, but then it's an artistic choice; vinyl forces de-essing upon you. If you want to keep aggressive sibilance in for aesthetic reasons, and want to press to vinyl, you're out of luck. And when de-essing is achieved through re-recording vocals, it can alter the music in subtler ways, making vocalists deliver lyrics less intensely and lose a degree of artistic expression in the process.

What CDs can do

Since CDs rely on sampling an original analog signal being recorded, they do have some frequency limitations. While vinyl records, in theory, directly encode a smooth audio wave, CDs sample that audio wave at various points and then collate those samples. "No matter how high a sampling rate is," Wired's Eliot Van Buskirk once wrote, "it can never contain all of the data present in an analog groove."

That's true. CDs work by taking a bunch of samples from a source audio wave and stringing them together. But this criticism is misleading on two counts. For one thing, vinyl pressing is not error-free, and the analog groove of a given record is not a precise replication of the audio wave recorded in the master, not least due to extreme high and low frequency limitations. It's true that CDs can't exactly replicate the whole audio wave in a master, in every case (update: in many cases, the Nyquist-Shannon theorem means it can) — but neither can vinyl records.

More importantly, the volume of sampling that CDs do should be enough to get a replica of the original recording that sounds identical to the human ear. The sampling rate for CDs is 44.1kHz, meaning that CD recordings sample the master recording 44,100 times a second, and can capture frequencies as high as 20 kHz. That is about the limit of what humans can hear; at least one experiment has confirmed that listeners in blind tests can't tell the difference between recordings that include frequencies above 21k and ones that don't. You may think you can hear more than CDs are giving you. But you probably can't.

And over time, engineers have come to make better use of those 44.1kHz. Scott Metcalfe, director of recording arts and sciences at Johns Hopkins's Peabody Institute, explains that engineers have taken to "oversampling," making digital files that use a much higher rate than 44.1kHz, and then compressing that back down to 44.1kHz for the actual CD. "It captures the signal at a much much higher sample rate and then mathematically takes it down to 44.1kHz," Metcalfe says. "It does a really good job of preserving information."

Metcalfe brings up another problem with this line of CD criticism. Even if an actual recording method can hold frequencies above 20kHz, that doesn't matter if there isn't a microphone capable of capturing them in the first place, or a speaker capable of playing them back. And most studios don't have microphones that record above 20kHz, and it's very rare for speakers to play frequencies above that. Indeed, most playback systems feature low-pass filters, which specifically cut off anything above that marker.

The fact of the matter is that CDs can create closer facsimiles than vinyl can.

What do people actually prefer?
There is, sadly, no Pepsi challenge for CDs and vinyl. Image courtesy of Pepsi.

Simply as a matter revealed preferences, the fact that Americans buy digital copies of songs at a much greater rate than alternatives suggests that they'd rather listen to digital music or CDs than vinyl. Taking both actual albums and track sales into account, the equivalent of 243.5 million digital albums were sold last year, compared to 165.4 million CDs and 6.1 million vinyl records. Given that compressed digital audio is considerably lower in quality than either CDs or vinyl, consumer certainly seem to care a lot less about audio quality than convenience.

But that's kind of an unfair comparison, given exactly that convenience differential. You can't fit thousands of tracks' worth of vinyl in your pocket and listen to it while jogging. So what happens if you set all else equal, and have people compare digital and analog audio in a controlled setting?

Unfortunately, no one appears to have done a double blind listener test comparing vinyl to CDs, but there is a good study from Florida State's John Geringer and Patrick Dunnigan doing that with CDs and high-quality cassette recordings. While cassettes sold to consumers often featured lower audio quality than vinyl records, there's nothing inherent to magnetic tape requiring that, and the format doesn't suffer from the frequency limits imposed by the risk of vinyl skipping. It's not a perfect test for our purposes, but knowing how people feel about high-quality analog stacked up to high-quality digital should tell us something about comparing vinyl to CDs.


Geringer and Dunnigan used identical microphone and mixing board setups to record four different concerts, each time using both a digital record and a high-quality analog cassette recorder (the MR-3 from audiophile favorite brand Nakamichi). They then had 40 music majors listen to the recordings, either with loudspeakers or headphones, while letting them switch between each recording at will. The test subjects were not aware of which was the digital recording, and which was the analog one. They were then asked to record their preferences.

It turns out that the music majors had a significant preferences for digital. "Participants gave significantly higher ratings to the digital presentations in bass, treble, and overall quality," Geringer and Dunnigan write. The results were weaker on some points than others (recordings of string orchestras were a particularly close call) but in no case was the average rating of the analog version higher than the average rating of the digital one. The most analog-generous thing to be taken away from the study is that there are some types of music for which people have no preference. But there were several where people had a real, noticeable preference for digital.
So why do people love vinyl?

Record enthusiasts rapidly search through boxes of vinyl records on the opening day of the annual WFMU's Record Fair, which benefits that noncommercial radio station based in Jersey City, on November 22, 2013 in New York City. Photo by Spencer Platt/Getty Images.

Perhaps the best audio-based case for vinyl is actually precisely the fact that it does mess up the original recording. A lot of vinyl fans talk about the "warmth" of records, particularly of the low-end. But, as Pitchfork's Mark Richardson puts it, "the 'warmth' that many people associate with LPs can generally be described as a bass sound that is less accurate." The difficulty of accurately translating bass lines to vinyl without making grooves too big means that engineers have to do a lot of processing to get it to work, which changes the tone of the bass in a way that, apparently, many people find aesthetically pleasing.

"Warmth" also comes from flaws in record players. As the University of Waterloo's Stanley Lipshitz once explained to Popular Science, speaker sound and the needle's height fluctuations can cause the record to vibrate, which the needle in turn picks up and translates into a "warmer" seeming sound.

Is it wrong to prefer that "warmer" sound? Of course not! It would be as preposterous to rule that out as a legitimate source of aesthetic appreciation as it would be to discount distorted guitar lines for being "less faithful" to the original guitar sound. Audio distortion can be beautiful and there's nothing wrong with liking it. But there's also something to be said for listening to music as its creators meant it to be heard, and precisely because of their "warmth" vinyl recordings sound rather different from what artists hear in the studio.

"As a recording engineer, when I go to a digital recording, what I did is exactly what I get back," Metcalfe explains. "When you record in the analog domain, what you're hearing there is different from what you sent in."

Should I stop listening to vinyl?
Jack Black has strong opinions on the virtues of vinyl. Clip from Touchstone Pictures.

No! For heaven's sake, no. Each format has its charms, and their overall differences in quality are often overwhelmed by differences in the quality of initial recording equipment, in mastering approaches, and in playback setup. But if you're a vinyl collector, you also shouldn't go around telling your friends how much purer your audio is. First off, that's generally dickish behavior, but more to the point it's false. Digital recording just is more accurate. That's not the only thing worth considering by any means, but it does make the puritanism of some vinyl true believers look rather ridiculous.

Thanks to Paul Gold of Salt Mastering for help in researching this piece

Source: https://www.vox.com/2014/4/19/5626058/vinyls-great-but-its-not-better-than-cds

McIntosh MAC7200 Receiver - $7,500










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