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Scanning Question


James Gordon

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Hi,

 

I have 5 100 foot rolls of 16mm Kodak sitting at Fotokem, and I'm trying to decide on a scan option.

So my end goal is to put it on Vimeo, and upload it to facebook, or eventually upload as high quality a file as possible onto my own website. That said, I have a question about DPX scanning vs telecine.

 

I'm going with 4k. Is it worthwhile to get a DPX scan, and then have that turned into a DNxHD file, for the internet? Obviously having the uncompressed files in possession is cool, but is this a normal practice? As opposed to just doing a straight data telecine scan.

 

 

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I supposed your options would be:

1. 4k DPX scan > 4k video file

2. 4k DPX scan > 2k/HD video file

3. 2k DPX scan > 2k/HD video file

4. Telecine > 2k/HD video file

 

You would have to decide if you think the 4k is worth the cost for future archiving, etc. I would definitely get a scan of some kind though, a telecine will produce a softer image with relatively poor registration, more compressed colors, and much less dynamic range than a scan.

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Depending on the scanner being used and the pricing, why not do both? We can scan to DPX and ProRes simultaneously on our ScanStation, and it's only a little more per foot for the second file. No reason not to do 4k DPX for archiving and 4k ProRes for working with. I mean, unless you don't need archival copies, then I'd just stick with ProRes 4444 or something similar.

 

-perry

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With S16mm, I simply ask the lab for a 2k scan and deliver a 2k Pro Res 4444 file in RAW color space.

 

You'll not only save a LOT of money by doing this workflow, but there is no need for DPX camera originals unless you plan on scanning the project back out to film. I've done a lot of experimenting with deliverables for cinema projection using DPX and Pro res. I've found the 2k Pro Res 4444 mastering for S16mm to work very well. Once done with color, you can make a DPX file out of DaVinci and that can be your "archive master" of the film.

 

In terms of 2k vs 4k… S16mm resolution is right around 2k. The less grainer the stock, the more perceptible resolution you'll have. So if you shot 50D for instance, you may have a tiny bit more visible res then 2k. However, if you shot a 250 or 500, you'll be capped out at around 2k of resolution. When you scan at 4k, all you're doing is introducing more noise into the image. I've done some camera tests with 2k and 4k scans and I would never scan S16 at 4k again. It just eats up bandwidth through flickering grain, which is unnecessary. Sure, if you plan on scanning back to 35mm, then you'd want that resolution. However, if your ultimate goal is DCP and internet distribution, I'd stick with 2k so your image is more "digital friendly" and you won't be wasting bandwidth on some reflective particulates.

 

'Rogue Nation' was shot on 35mm and finished in 2k. So if it's good enough for a feature film in 35mm, it's good enough for 16mm. ;)

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Any opinions on a spirit scanner at 2k?

 

Also, I'm using Adobe premiere elements for editing. I don't understand the difference between dnxhd files vs. Pro res. How critical is this?

 

And for color grading, if I were to get a flat 2k scan, would I be handing a pro Res file to whoever color grades it? I keep reading about how people use a local colorist, what does this entail? Giving them the compressed file?

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Spirit 2k is fine, they work well.

 

DNX is an Avid proprietary format. So if your editing with Premiere, you'll be wanting Pro Res as your computer won't even playback DNX files.

 

You will cut the show in Pro Res 2k 4444, consolidate (copy) all used media onto a drive using MXF or EDL and hand it over to the colorist.

 

The colorist will import the MXF into DaVinci and do the color.

 

They will then export three things:

 

- Pro Res quicktime movie of the final

- Pro Res colored shots (to replace the stock shots in your editing program)

- DPX file for archiving

 

You will then take that pro res quicktime and import it back to your timeline in Premiere, mate it with the sound and export your final product in Pro Res 2k 4444.

 

I don't know if Premiere can export in 2k 4444, but it should be able to if you import in that format. You will need the proper pro res 2k codec's, which are not included with the operating system. I'm not sure if Premiere comes with them, but it might.

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Pro Res codec's are available for Windows, Linux, Mac and are free.

 

Avid DNX codec's are only available for Windows, Mac and are tough to find without dealing with Avid.

 

The only editing software that works with DNX is Avid. I've tried to make FCP and FCPX work with DNX, but the rendering engine has some issues. Pro Res is native to Avid, Final Cut Pro, Final Cut X, After Effects, DaVinci and Premiere, so it's a no brainer. The render engine has been built to work with pro res and it does a good job.

 

Honestly… I wouldn't edit "film" on anything else but Avid anyway. It's the only software that allows you to catalog and deal with keycode, which is critical for going back to the negative. Maybe not so important for today, but nice to have years down the road when your film is a cult classic and you wish to restore it. I edited my films on FCP and I can't go back to the negative to save my life. So to re-cut (up-res), I've gotta scan everything, which is a real costly endeavor if you have 20,000 feet worth of film and only need to scan 1700.

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I have to disagree that 4K is not necessary for super16 and definitely disagree that it "adds noise". What you are seeing is properly resolved grain as opposed to a softened image that didn't resolve the grain. Believe it or not, this becomes more important the smaller the gauge because the grain is more prevalent to begin with. You can get away with it better with modern 35mm because the grain is so fine anyhow that it's not a major contributor to the image. I scan super 8 at 5K and master in 2K for HD output. The image just appears "sharper" because there is 5K worth of relevant information... That information being grain. Even though the photographic information is not 5K it does take that level to not mess up the grain.

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I would scan cineon or log gamma to Prores4444 at 2K, you won't gain much if anything by scanning 16mm at 4k.

Also Prores 4444 is 12-bit where as dpx cineon would be 10-bits. You can play prores on both mac and PC as well.

I scan my 16mm stuff here on the scannity 4k HDR and am always happy with the results.

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I have to disagree that 4K is not necessary for super16 and definitely disagree that it "adds noise".

Well, it's true if you actually think about the comment instead of being offended…

 

If you were to cut the negative and make a 16mm print, you'd have MUCH less grain.

If you were to blow up that cut negative to 35mm, you'd have MUCH less grain.

If you were to scan at 1080p or 2k, you'll have less grain.

 

So basically, by scanning at 2k (which is higher resolution then the actual image itself in most cases) you aren't capturing anymore "pertinent" information, you are simply capturing more noise, more grain. Then to make an acceptable image, you're running it through noise reduction. Where, if you just captured it in 2k to begin with, you wouldn't need to go through that process.

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I was not offended. Just disagreeing.

 

Especially when talking about 16 and 8mm grain is part of the image and I would never de-noise or de grain it in post other than for web-based streaming where it would be mucked up anyhow.

 

For me, the grain is not noise, it's part of the look that I am going for when I shoot these formats. Plus, if I were going to remove the grain I would want to control that removal, not leave it to a limitation of my scan to do it for me in a way that softens the image.

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I just did some test scans at Metropolis Post, today. My negative is regular 16mm and they put up a side-by-side comparison of my film (on a huge screen) at 2K and 4K. I have a very discerning eye and I have to say I really couldn't see the difference. Considering the significantly higher cost of 4K, you really won't be gaining much, if anything, in your image. So it looks like I will be finishing with a 2K scan there.

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I just did some test scans at Metropolis Post, today. My negative is regular 16mm and they put up a side-by-side comparison of my film (on a huge screen) at 2K and 4K. I have a very discerning eye and I have to say I really couldn't see the difference. Considering the significantly higher cost of 4K, you really won't be gaining much, if anything, in your image. So it looks like I will be finishing with a 2K scan there.

 

Bill,

 

When they did the scan, were they doing a true 2K scan or simply taking the 4K scan and outputting it to two different formats (one 2K and one 4K). Their Director is capable of doing this so I imagine they simply scanned at 4K and wrote to the two different formats.

 

If that's the case, you are correct. It is highly unlikely that you would see the difference projected on a screen because you would not have the grain aliasing issue as bad as an actual 2K scan. The original data was there and the software then do-ressed it. Keep that in mind if you request a 2K scan... it may not look the same as your most recent 2K scan if the 2K scan wasn't really a 2K scan but a 4K scan down sampled to 2K.

 

FYI, no one beats Jack, Metro Post and the Director in my opinion... especially scanning print and color reversal. Beautiful dynamic range, color and sharpness.

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scanning at 2k (which is higher resolution then the actual image itself in most cases)

 

 

This is not accurate. It's a longstanding bit of incorrect "common knowledge" that 16mm is 2k, 35mm is 4k, etc, etc, but it's simply untrue. There is no way one can say X film gauge = Y pixel resolution, because film isn't made of pixels. That's an apples to oranges comparison.

 

Film grain is an organic shape. It's not a square pixel. If you want to get an accurate representation of that grain, you need more pixels to properly render all the subtle details, curves and variations.

 

Let's pretend you're a scientist working with nanoscale-level material. Are you going to use an optical microscope like you'd use in a biology lab, or are you going to use a scanning electron microscope, if you want to get an accurate picture of what you're looking at?

 

Sure - in practice, if you look at a 2k scan projected with a 2k projector, and a 4k scan projected with a 4k projector, assuming both are correctly calibrated and you're viewing at the correct distances you *shouldn't* see any difference between the two. But if you get close up, you will. It's the same as 1080p and 720p. Once you're past a certain distance from the screen, your eye simply can't resolve enough detail to discern a difference. But if you increase the screen size or get closer to it (imagine a 60" television 6 feet from a couch, not an uncommon situation), then you clearly see the differences.

 

So what does that extra resolution get you? Better grain resolution, as mentioned. Since the grain *is* the image, why wouldn't you want this? Even if the end product is destined for a lower resolution, you're better off scanning at a higher res and downscaling it anyway. More photosites on the sensor mean you have more points picking up the fine details and that can mean not only increased sharpness, but slightly better dynamic range (again because you're able to render a single grain of film with more than one or two pixels like you'd get with a lower res scan).

 

But much of this arguing about resolution is kind of silly (the number of pixels are only one of many factors here - optics, dynamic range, transport stability of both camera and scanner, and registration quality are all arguably more important), I'll say that to me the most compelling reason to scan to 4k is to avoid having to scale up later. 4k televisions are under $1000 now, and they're going to replace HDTVs (unlike all that 3D nonsense being pushed on consumers a couple years ago). When you have a gigantic 4k screen and you're close to it, you're going to see softness from upscaling the image from a 2k scan. 8k TV isn't that far off. The less you have to blow up the image in the future, the better, and there's no real downside to downconversions for use on current systems.

 

It makes no sense to me to *not* scan at 4k right now based on this argument alone.

 

-perry

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When they did the scan, were they doing a true 2K scan or simply taking the 4K scan and outputting it to two different formats (one 2K and one 4K). Their Director is capable of doing this so I imagine they simply scanned at 4K and wrote to the two different formats.

 

This is an excellent point. Our Lasergraphics ScanStation can do the same thing (output to multiple formats at once). A 2k scan made with the scanner in 2k mode (a 2.5k window in the center of the 5.1k sensor) does not look the same as a 2k scan made with the scanner in 5k mode, where all 5.1k photosites are used to make the image.
Here's an example of the difference, from some Super16 footage: http://www.gammaraydigital.com/blog/case-super2k
I'm not certain, but I think the Director may always operate in 4k mode, downscaling the image to 2k if that's what you want. That said, if you're comparing it to another scanner that's operating at a native 2k, you'll almost certainly see a difference.
-perry
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This is not accurate. It's a longstanding bit of incorrect "common knowledge" that 16mm is 2k, 35mm is 4k, etc, etc, but it's simply untrue. There is no way one can say X film gauge = Y pixel resolution, because film isn't made of pixels. That's an apples to oranges comparison.

If you use a SMPTE resolution chart on a film camera, you will be able to understand film's actual available resolution. Sure, the chart is more line based then pixel count, but we can extrapolate pixel count based on the lines we see in the scanned image. This varies on stock grain density of course, but the tests were all done with 200T Vision negative. You can read more about this study in the paper called "Resolution of 35mm Film in Theatrical Presentation" http://www.motionfx.gr/files/35mm_resolution_english.pdf

 

Now, I do understand these tests were done with what we'd consider "antique and outdated" stock. Our modern stock is FAR superior in many ways. However, it's pretty conclusive that 35mm color negative has 2400 lines of resolution and since they were testing at 1.85:1 aspect ratio, and we know horizontal and vertical lines would be the same. We can extrapolate a theoretical maximum resolution of 4440x2400, which is slightly above 4k.

 

16mm is less-than half the size of 35mm, so that means it's right around 2k. With super 16 being being only slightly higher then that, only if low-grain stocks were used.

 

Now, I didn't take part in those tests, but I have done my own resolution testing as part of school. We found that 16mm negative had around 750 lines of resolution, using a very similar chart and projected onto a huge wall as a still frame, so we could really get detail. Yes, there are many variables in this discovery and modern stocks are better.

 

So this is where I get my "knowledge" from. A little bit of relying on other people's studies AND doing my own experimentation.

 

Film grain is an organic shape. It's not a square pixel. If you want to get an accurate representation of that grain, you need more pixels to properly render all the subtle details, curves and variations.

That I agree with whole heartily. But let me respond to my reasoning below…

 

I'll say that to me the most compelling reason to scan to 4k is to avoid having to scale up later.

First and this is a huge misconception, most television is 1080i/720p and we are damn lucky to have those resolutions. Within the current standards, it will be impossible to update to 2k, let alone 4k. Plus, there isn't a single true 4k consumer-grande television on the market.

 

Second, I recently did research for another thread and found out, only 40% of all movie theaters in the world have 4k projection. That means, most theaters are 1920x1080 or 2k and the vast majority of big hollywood theatrical films are finished AND distributed in 2k.

 

Third, streaming services which claim to be 4k like Netflix, Youtube and Vimeo, are a complete failure because to get that resolution through the already extremely limited bandwidth available to consumers, they have to compress the ever-living snot out of the images, making them very soft, negating any of that added resolution.

 

Fourth, digital cinema projectors use three imagers and there is zero percent chance they're calibrated. So even if you were to make a 4k DCP and rent a 4k theater, you aren't seeing anywhere close to 4k worth of resolution.

 

With that said, the only way to see a true 4k image is at one of the big color correction facilities in DPX on their monthly calibrated 4k projector. Even then, I've been pretty un-impressed with many of those facilities in Hollywood. There are only a few that have surprised me with decent projectors and resolution.

 

I understand for bigger theatrical productions where the filmmaker may not hold the rights to the negative and the film is guaranteed a theatrical run, you do want the highest quality possible for your budget. However, most people shooting S16 aren't doing big theatrical runs and the cost difference between 2k and 4k workflow is astronomical, for resolution they will never see outside of the lab where it was scanned. If their film does well, they can always go back and re-scan the negative at any resolution they want with the backing of a distribution companies piggy bank. This is why cataloging key code and reel numbers during post production is so important.

 

In summary, I agree that getting the highest quality master possible is important, but that's why you shot on film in the first place, that's your "master". For post production, you edit and deliver to the max resolution of your pre-planned distribution method. If that's blowing up to 35mm, then you cut the negative and blow up to 35. If that's television, you'll finish in 2k and down-sample to 1080i for broadcast. If it's internet/web, who cares what it is, damn thing will look like crap anyway. You can always go back and re-scan, you can always get more resolution out of your image as the imager resolution increases and the costs to use those scanners decrease. People put too much emphasis on resolution and not enough emphasis on how consumers will see that resolution.

 

P.S. I do plan on finishing my upcoming S16 film in 4k using the Blackmagic real-time scanner. This is simply because we will be doing theatrical and most of the film will be low-grain 50 asa stock, so you will see more detail in the image. So yea, you can call me a hypocrite! LOL :)

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Spirit 2k is fine, they work well.

 

DNX is an Avid proprietary format. So if your editing with Premiere, you'll be wanting Pro Res as your computer won't even playback DNX files.

 

You will cut the show in Pro Res 2k 4444, consolidate (copy) all used media onto a drive using MXF or EDL and hand it over to the colorist.

 

The colorist will import the MXF into DaVinci and do the color.

 

They will then export three things:

 

- Pro Res quicktime movie of the final

- Pro Res colored shots (to replace the stock shots in your editing program)

- DPX file for archiving

 

You will then take that pro res quicktime and import it back to your timeline in Premiere, mate it with the sound and export your final product in Pro Res 2k 4444.

 

I don't know if Premiere can export in 2k 4444, but it should be able to if you import in that format. You will need the proper pro res 2k codec's, which are not included with the operating system. I'm not sure if Premiere comes with them, but it might.

This has been a great thread, thanks to everyone. So I was going to have Fotokem do a 2k scan after all, but after clarifying to them that this is ULTRA 16mm, I got the following message:

 

Additional reminder that we cannot get all of the film info of the ultra 16mm.

 

The camera files out of the extra area next to the perfs are on the left side.

 

The Spirit does not have a skid plate to capture the image.

 

So... looks like the 2k Spirit scan does not accommodate Ultra 16mm. Is that correct?

 

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This is an excellent point. Our Lasergraphics ScanStation can do the same thing (output to multiple formats at once). A 2k scan made with the scanner in 2k mode (a 2.5k window in the center of the 5.1k sensor) does not look the same as a 2k scan made with the scanner in 5k mode, where all 5.1k photosites are used to make the image.
Here's an example of the difference, from some Super16 footage: http://www.gammaraydigital.com/blog/case-super2k
I'm not certain, but I think the Director may always operate in 4k mode, downscaling the image to 2k if that's what you want. That said, if you're comparing it to another scanner that's operating at a native 2k, you'll almost certainly see a difference.
-perry

 

Hi Perry,

 

Does your scanner and Metropost's Director accommodate Ultra 16mm?

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Just from practical experience, I side with people who feel that 4-perf 35mm negative film is roughly a 3K system effectively in terms of resolution. Brad Hunt of Kodak did tests in 1990 to determine the optimal resolution for their Cineon digital intermediate system and looking at MTF charts, they determined that there was very little improvement in resolution once the scan hit 4K, in fact, they only saw a 3% improvement between a 3K scan and a 4K scan, hence why they picked 4K for their system.

 

I've seen some tests of line resolution charts and even with optimal prime lenses at optimal stops, 35mm negative seemed to be resolving about 3.5K worth of detail at best.

 

Of course, Nyquist would then suggest that if there is 3.5K worth of information, you need to scan it at 7K to avoid aliasing, though in real world subjects, it is hard to get aliasing artifacts with a 4K scan.

 

I know one studio who is doing their digital mastering work starting with a 6K scan on their Arriscanner. The IMAX DMR process usually begins with a 6K scan of 35mm when they aren't working from a digital master already done by someone else.

 

As for why not scan 35mm at 8K or 12K for that matter, the main reason is money, at some point there are diminishing returns.

 

And again, keep in mind that a 2K scan of 16mm is the same pixel resolution as a 4K scan of 35mm -- saying that 16mm should be scanned at 4K is like saying that 35mm should be scanned at 8K. Maybe you can make a case for that, but it's a bit overkill for most real-world photography so unless money is no object, I don't see why a 2K isn't good enough for 16mm.

 

The scaling argument though is interesting, but on the other hand, I suspect that in a 4K distribution system, 16mm footage scanned at 2K and up-sampled to 4K isn't going to look that different than a 4K scan. However, a 4K distributor who has a "no upscaling allowed" rule for their 4K acquisitions would therefore probably want a 4K scan, whether or not there is actually any advantage to it for 16mm material.

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Pro Res codec's are available for Windows, Linux, Mac and are free.

 

Avid DNX codec's are only available for Windows, Mac and are tough to find without dealing with Avid.

 

Where can I find a ProRes codec for free on Windows? DNxHD is free and cross platform, but I haven't been able to find a free ProRes for Windows.

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While high definition scans don't necessarily improve much on the perception of details in an image it does improve the grain. And the bit depth - making the image more gradeable in the grading pipeline.

 

This has been demonstrated in the Super8 domain where 4K scans of Super8 are becoming the norm - the main reason being improvement of the grain. Because in Super8 the image is very grainy - because while the same stock as used in 35mm, it is magnified so much larger - so any improvement is far more noticeable.

 

So while it sounds crazy (4K scans of Super8??) it's just because it is more noticeable how more improved the image looks.

 

And there is a valid argument to say that the less grain there is the more information there is making it through.

 

So this whole model of quantifying film in terms of pixels per mm is somewhat flawed. It is pixel per image that is a better model. Super8 benefits from 4K scans as much as 35mm benefits from such. Indeed more so.

 

This does not mean Super8 has the same amount of information as 35mm.

 

All it means is that where 35mm finds 4K scans an appropriate sweet spot (cost/return etc), it does not mean Super8 therefore finds the same sweet spot at 1K.

 

C

Edited by Carl Looper
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Where can I find a ProRes codec for free on Windows? DNxHD is free and cross platform, but I haven't been able to find a free ProRes for Windows.

 

I was using a Windows version of ProRes for about a month and then the company making it called it quits. Not sure why (perhaps some license issue).

 

C

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