How an HD transfer of an old movie is done?

[Sean Mota]

Looking at The Sound of Music last week on ABC, I thought it looked good despite being a movie made in the 1965 and comparing it to a movie like Easy Money made in 1983 which, imo, looked ok but had bad looking moments in the HD transfer, make you wonder why?

Is it because the manner in which each original film was preserved? or is it because different procedures are used to tranfer the film to HD? Can anyone outline from beginning to end how this is done or give us some insight from the engineering perspective?

 

[mike123abc]

Well the process of making it HD is probably close to exactly the same in both cases. A telecine machine is used to digitize each frame of the movie. The film reels are cleaned and lubricated before they are loaded into the telecine machine, then each frame is scanned to hard disk. The operator of the machine then does general color correction.

The problem you are seeing has to do with both how it was preserved and what film/chemical process was used originally.

Here is a long article by the Library of Congress on film preservation covering the various processes and how they hold up over time. Technicolor seems to be a winner: http://www.loc.gov/film/study.html

 

[Sean Mota]

Mike,

thanks for that article. It is long but very informative about film preservation. I was not able to read it all but did scan through the issues.

I have tried to look for more information about this but I have yet to come across a document that can explain the whole process from film==>storage==>preservation==>HD transfer.

I was looking at another forum and I am going to quote someone from that forum. I've received permission to quote him.

Film is typically either 4K or 2K resolution. Most film is shot 2K these days. When it is shot 2K the total resolution is 2048x1536 but that rarely gets used completely. More typically the film is matted to Academy (instead of full aperature) width during the shoot (in camera) and the resulting resolution is around 1828x1371. On top of this is film grain. Film grain will typically give you an effective resolution (what the consumer sees in the theater) less than the total resolution of the film for a number of reasons, most of which are mechanical.

Check out the following page for some background on film resolution.

http://millimeter.com/ar/video_digital_cinemas_special/

Older films have even more problems as they have larger grain, may have suffered damage due to improper storage or through the print process and they will have less dynamic range than current state of the art film processes. The problem is that Hollywood no longer wants to shoot on state of the art film anymore. Film (the medium) is itself so much a part of the production costs of the feature that studios have elected to cut many corners in the 'film' process and have resorted to digital for many aspects of the production. Some of this is good, some not so. Anyhow, I digress. HD, and I mean real *uncompressed*, 10 bit HD will stand toe to toe with film any day of the week when it comes to the viewer experience. You only have to attend a side by side showing of a pure digital production against the traditional film production to appreciate the remarkable advantages that digital productions have. Again I am droning on and I apologize, but the point I was trying to make is that there is not as big a difference between HD and 'film' as one might think in terms of resolution (dynamic range is altogether a different beast).

The reason that it is easy to transfer film to HD is because they have the same native frame rate (24Fps progressive) and they are nearly identical in resolution.

The 1080p 24 fps master standard was designed to transfer frame for frame from film originals. It is the universal master and the highest resolution possible due to the limits of modern processor speeds and hard drive capacities.

Don't you even fret about a 1080p TV broadcast or a 1080p HD DVD release (unless of course you can watch it aboard NCC-1701...

The 30 fps (29.97) was designed for TV and all films are converted to it for broadcast.

A little more background on this, the main reason that 1080/24Fps made it as an ATSC standard was because the HD folks wanted to push it as a replacement format for international television production. Most high budget commercial and television production is shot on film. This allows them to easily move between NTSC and PAL distribution formats. Because the industry is used to this workflow and everyone (the consumers) are accepting of the results, HD HAD TO have a compatible format in order to be considered seriously by the 'film', television, and advertising industries. Its not so much that they expected their to be a lot of Film ->HD transfers going on, its that they expected new product to be shot natively in HD at 24Fps and then the rest of the workflow (post production/editing) could simply treat it as they would native film. This is as much about the politics and perceptions of the production process as it is about any technical advantages so the HD guys simply had to follow the herd in this instance and come up with a acceptable substitute.

I think if we can wipe the blackboard clean and forget NTSC interlaced 30 fps and work on a HD standard of 720p 24 fps we will eliminate a lot of conversion artifacts/anomalies.

Let the studios keep 1080p for our grandkids...

720P/24 is an interesting thought but the temporal accuracy sacrificied is just not worth the net gain in simplified image processing. 720p/60 will result in far fewer artifacts and it is available today.

I went to a seminar given at Paramount which compared and contrasted HD and Film, or more correctly digital projection and film projection. This was a predominantly pro-film rally with very few HD people in attendance. There were all the normal comparisons of aspect ratio and aperature and the film guys all complained about how HD (16:9) did not convey the full integrity of the directors vision (blah blah blah) all of which is obvious and true. The end of the seminar showed back to back comparisons of film vs digital projection on both existing material and material that was shot just for this exhibit. The digital projection material was predominantly HD but there was quite a bit of 2K digital as well. Keep in mind that this was digital, 10 bit, uncompressed HD and 2K footage on a $100K projector. The difference between the two ranged from extremely subtle to almost laughably obvious. The digital projection won out at every turn, largely due to the stability of the image (no wobble issues here). What was more telling however was that the scenes that were shot 1080p30 and even more so, 1080p60 were simply mind blowing. Even the most devout film purists were slack jawed at the difference in the viewer experience. My favorite quote was from a famous director who stated simply "It was too real, the audience won't be able to handle it" when asked about 1080p60. He was implying that the lack of temporal information in a 24P production allowed the audience to adopt a level of disbelief, allowing themselves some distance from the experience. Anyhow, I have droned on enough.

My background is working with both film and HD. I was a hardcore Film purist until I saw what could be done with proper HD equipment. We are a long ways from seeing what is possible with HD as their is an entire generation of technical specialists which need to re-learn their craft to take advantage of HD. (everyone from lighting directors to DOPs and set designers). In the end we will be the better for it when (if) hollywood adopts HD.

Anyhow if you aren't going to the cinema much lately I doubt its because your being picky about the quality of the visual experience there. Its more likely that the material sucks and that like me, you can get almost the same experience from your home theater (and spend less money) and that says tons about the potential of HD, as you are not experiencing what is possible with HD in any home setting, not yet anyhow.

 

[mike123abc]

Well the main problem was that for years a film once shown in the theater and then maybe television it was useless. They were stashed away all over the place in less than ideal conditions.

Then it turns out that film prior to 1950 becomes very volatile as it ages, hence explosions and fires at many old film storage places wiping out old films.

VHS probably saved many old films, once the studios realized that old films could be sold over and over, it became worth it to store them correctly.

http://www.cintel.co.uk/ makes telecine machines, they have brocures and white papers

 

[Sean Mota]

Mike,

thanks for that link. I'll be doing a lot of reading.