A Guide to Scanning Motion Picture Film

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During my days as a film student, I shot projects using film and digital media. While digital footage was imported directly from tape, film was sent out, developed, and transferred to tape in standard definition. Now that more than a decade has passed and the industry has gone predominantly digital, what options exist for people looking to transfer their existing film? The answer is: film scanning, but how does this differ from the older telecine process? Before undertaking this journey, users will need to be familiar with items such as film scanners, 2K versus 4K, frame rates, output methods, color grading, incurred costs, equipment needed, and more.

Telecine versus film scanning

A telecine is designed to work in real time. The film is played back at normal speed, captured at video or HD resolutions in the proper color space, color-corrected in real time, and written to disk or tape. The speed at which the film is transferred is the native speed of the recipient video format.

Film scanning, on the other hand, is a post process that captures each frame of film to its own file, or to frames of a movie file format such as QuickTime. The result is a significantly higher-quality image compared to telecine, with greater flexibility in post production. The speed at which scanning happens is determined by the speed of the sensor and the resolution, such as 4K at 15 fps or 2K at 30 fps.

Blackmagic Design Cintel Film Scanner

Selecting a lab / film scanner

Choosing where to have your film scanned is an important part of this process, and requires some research. I spent months researching labs and film scanners, eventually settling on a New York-based lab for two reasons: 1) I could drop off and pick up my material personally and, 2) their film scanning was done using a Scanity—a continuous-motion, sprocket-less line imager that uses optical pin registration, a TDI (time delay and integration) sensor, and a spectrally optimized LED light source. HDR scanning is also possible, but this is generally only useful when dealing with high-contrast prints, as opposed to lower-contrast negatives. It is also able to capture audio and more.

Line imagers, area imagers, and pin registration

The Scanity operates by taking a series of narrow images and assembling them into a single frame as the film passes by. This differs from an area imager, such as the Lasergraphics ScanStation, which takes an image of the entire frame at once. Additionally, the Scanity uses optical-pin registration to ensure that each frame is digitally aligned in the sequence using the edges of the sprocket holes as reference points. This differs from mechanical pin registration, where a metal pin holds the film in place, and is a gentler process, especially for older, damaged film.

Sprocketless Optical-Pin Registration

Scanning resolution

Image resolution is all about Ks (2K, 4K), but what does the “K” mean? It refers to the number of picture pixels contained in one complete horizontal line of a digital image. A 2K film scan will typically result in 2,048 horizontal pixels per scan line. When a full-aperture Super 35mm film frame (1.33:1) is scanned at 2K, this results in a resolution of 2048 x 1536; while a 3-perf 35mm film frame (1.77:1) produces 2048 x 1157. Both are considered 2K, even though they have different vertical line counts. So, the “K” in film scanning refers to the number of “finished picture pixels” contained in one horizontal scan line, regardless of the vertical count.


16mm Kodak Vision 250D, scanned at 4K
4-perf Super 35mm Kodak Vision 100T, scanned at 4K

Many argue that 35mm can resolve up to 8K and that anything over 2K for 16mm isn’t needed, while others argue that scanning 16mm at 4K can help with precise detail rendering. I had both my 16mm and 35mm film scanned at 4K. The Scanity used was equipped with a Super 35 Full Aperture gate and a Super16 Full Aperture gate, meaning each gate is optically centered for the middle of the full film image with no academy framing offset. Film is scanned full width, since that is what the sensor is optically set for, with 2K or 4K scans using the full sensor width at that resolution, not the smaller academy film frame aperture. An academy aperture gate would have the sensor calibrated exactly for the academy film frame size and not the full aperture frame.

Since my 35mm material was shot as 4-perf Super 35, a Full Aperture gate was fine, since film shot in a camera with a gate modified as “Super” takes advantage of the negative’s full width, including the area usually reserved for the soundtrack. However, for 16mm film, this Full Aperture gate meant that Super 16 framing would be used and sprocket holes would be visible down the right side, making it necessary to perform digital rescaling after the scanning process. In the end, my 35mm material was scanned with a resolution of 4096 x 3112 and 16mm material had a scanned resolution of around 3.6K wide, after being trimmed down from the 4096 x 2480 image size of Super 16.

Bear in mind that 1080p HD scans should be avoided, since they only provide a 16:9 image. If you’ve shot a 4:3 image, it will not capture the entire frame.

Frame rates

The frame rate at which your film is scanned is generally related to how your film was shot and your desired final output, such as DVD, Blu-ray, or a QuickTime movie. All my film was shot at 24 fps, but my initial transfer was done at 30 fps since dailies were delivered on Beta SP. Consequently, sound was also recorded at 30 fps.

I opted to have the scanning done at 23.98 fps and not true 24 fps. I did this because Adobe Encore, which can create Blu-ray media, is not compatible with material shot at 24 fps. While I was concerned that my original 30 fps audio would not sync with 23.98 fps, this turned out to be a moot point, as one second of audio is one second of audio, no matter what the frame rate.

4K versus 2K

I also had 2K scans made, with the goal of finding out if 4K really made a difference. I found that for 16mm and 35mm film, 4K scans were of higher quality than 2K. When comparing a native 2K scan to a 4K file down-res’d to 2K, they looked similar, but 2K files that were up-res’d to 4K did not hold up as well as the native 4K files.

16mm Scanned at 2K
16mm Scanned at 4K

QuickTime versus DPX

Once the scanning process is complete, your film can be output as either DPX files or a QuickTime movie. Very similar to the RAW files used in digital photography, DPX files are uncompressed 10 or 16-bit raw scans that support logarithmic or linear color spaces. One DPX file exists for each frame of film. If you opt for QuickTime files in the linear color space, it’s recommended to get them encoded as 12-bit ProRes 4444.

While DPX files provide the highest quality, they also take up large amounts of storage and require fast disk arrays for playback. My 2,000 feet of 35mm (about 20 minutes) took up 300GB in ProRes 4444 and 1.6TB in DPX. Larger files sizes also lead to increased times for rendering files and copying them to your drive. While color correction, VFX, and compositing software can work with DPX files, NLEs such as Final Cut cannot—at least not without third-party plug-ins.

Color grading

Scans are delivered as “flat,” meaning no color correction is applied to the image on capture. The resulting picture is somewhat washed-out looking and requires a second pass in a color-correction system. The advantage of doing a flat scan is that you don't “bake” color-correction decisions, which you may want to change later, into the digital files. This gives you more flexibility in post production.

A graded film scan
An ungraded film scan

So, what are your grading options? Most NLEs have at least basic color-grading tool sets, which can be expanded using third-party plug-ins such as Magic Bullet Suite 12. Blackmagic even offers a free version of its professional color-grading application, DaVinci Resolve, which supports output resolutions up to 3840 x 2160. If you’re not an experienced color corrector, you could hire someone to grade your footage, or just have the material needed for your final cut corrected.

Associated resources

The computer you’ll need to process your film scans depends on the “K” of your material. The bitrate for 35mm 4K material was 1.66 Gb/s and 1.3 Gb/s for 16mm, while 35mm 2K bitrates were 425 Mb/s and 340 Mb/s for 16mm, so multi-core systems like the 2013 Mac Pro are well equipped for this type of work. For those who prefer Windows, there is HP's Z840 Series. When working with 4K material, a dedicated hardware RAID is also recommended, such as the Areca ARC-8050T2. If you want to try your hand at film scanning, B&H also sells the Blackmagic Cintel and the accompanying 16mm and 35mm film gates.

In the end, the decision to have your film scanned, as well as the choices made along the way, is nothing to take lightly. ­Additional costs may be incurred for processes such as film cleaning, scanner setup, scanning time, and copying material. You’ll need to provide the lab with a drive on which to copy your material and also need an editing system capable of working with the material. However, a high-res film scan can also help you see your material in a new light, rendering a very natural grain structure with increased detail and dynamic range.

13 Comments

I had some 8mm & super 8mm films scanned at 2k resolution and some of the footage has vertical bars/lines in it (like what they add sometimes to make video look old). Can I get rid of them with Adobe Premiere or some other software? 

Hi Mike -

Please e-mail us:  [email protected]

Can you recommend a company that will do a fine quality scan of a 16mm film to 4K located in NYC. Thank you. I have the negative of a film I want to re-work in 4K.

We're not sure where you can get this type of service done in New York, but our only recommendation at the moment would be to do an Internet search with those terms and see where it brings you. Good luck, and please let us know what you find out.

This is a very informative article that I found most helpful in my quest to get the best results from old 16mm film.

I very much appreciated your article and would like to ask you a "terminology" question. My agency needs to transfer all of our video and 16mm archives to digital. I have to write a list of specs (scan rates, resolution, processing, outputs, etc) to put out the job for bids. Is there a standard set of terms for each phase of the conversion that would mean the same thing to each vendor? For example, is a requirement for a "2K" scan rate always going to produce the same level of quality?

The resolution of 2K is generally considered to be 2048x1080, which is half the resolution of DCI 4K at 4096x2160.  That being said it is better to specify the actual resolution over a name like 2K or 4K.

Excelelnt article...Thanks!

A great article indeed.  My situation is quite a bit less demanding I hope.  I have about 3 hours of Super 8 home movies in 19 reels of varying sizes, some with sound some without.  I'd like to have them transferred to a suitable digital format for archiving and distribution to family.  Some colour correction would be good for the older stock.  Having read your article and a few others, I realise there are many providers out there that use nothing more than a projector and a camcorder.  That sounds rather primitive and not at all what I was expecting but perhaps I'm kidding myself.  What do think my best options are and what would be a suitable digital format for my needs?

Regards

Hi Bob,

Thanks for your interest in my article. It's been a while since I had my film scanned or even did any research into this, but one place I'd definitely recommend for your needs are Gamma Ray Digital in Boston, MA. I spoke a lot with them while I was doing my initial research, but at the time, while they a LaserGraphics ScanStation, it wasn't able to scan at 4K. I also didn't want to ship my negatives anywhere and risk losing them, which was why I ended up using Nice Shoes here in NYC. However, the trade-off of using Nice Shoes, which does a lot of commerical work, and their 4K-capable Scanity with greater dynamic range was a higher price point, although being able to drop-off and pick-up in person was a bonus. I had also looked at Metropolis Post here in NYC and while they were a great deal cheaper than Nice Shoes and had a 4K-capable Lasergraphics Director, their software could only output 4K DPX files and not 4K QuickTime, just 2K QuickTime -- granted this was in 2015, maybe things have changed now. However, when I get around to the color correction phase, I would definitely look at Metropolis Post again.

Anyways, you're scanning Super8, which can be problematic, because a lot of these places that do film scanning are only in business because they handle large volumes of commercial work, and the Super8 market is such a small one. However, Gamma Ray has really stepped things up in the past few years. For Super8, they now offer edge-to-edge 5K scanning on a Lasergraphics ScanStation. 5K scanning is also offered for 8mm, 16mm, and Super 16, while 35mm 2-perf, 3-perf, and 4-perf film goes up to 6K.

So, I'd definitely look into Gamma Ray Digital. I'm not sure offhand of other places that offer this service, but let me know what you find and what you end up doing!

Dear john-Paul And B&H Friends, This is an excellent article And touches Many important subjects clearing many doubts, but It has a high Res Scanity as the player and not the Blackmagic scanner, which I would like To have a comparison of processes so I could make an educated evaluation for an eventual purchase. Would It be possible for John-Paul To use the same 20 minutes of film On a 4K scan Full gate for this comparison? I will be looking forward To such a test.

We'll look into it. Thanks for the suggestion!

Thank you!

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