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2016 - 2K or 4K for 16mm?


Brian Rose

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I'm in prepro on a documentary that I've been researching and prepping for the last two years. I'm shooting on 16mm black and white, and when I started, I figured I would scan in 2k and go from there. But now, in 2016, I'm not so sure. Between 4K in the theaters, and emerging 4K in television and streaming online, does it make more sense to scan in 4K now, invest upfront so I've got that master already set?

I've read different opinions on whether 16mm should be scanned in 4K. One camp says that 16mm really only has enough image information to warrant a 2K scan. Others say that a 4K captures more range and grain and resolves better when downsampled to HD. Or do I scan in 2K and upscale to 4K?

What do you all think?

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It really depends on your budget. A 4K scan will squeeze some more detail out of the grain, but not a whole lot more. When you look at side by side comparisons, you'll seldom see the difference unless you blow up considerably. It also depends on your scanner too. You might do well by having various post-houses do tests for you.

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A fine grain super 16 color negative can resolve around 2.5k. Same fine grain stock in square standard 16 is a bit more then 2k. Once you increase the grain structure with higher speed stocks, you loose a lot of the resolution. In fact, Vision 3 500T is only around 1k worth of resolution in super 16. So unless your shooting fine grain B&W negative in super 16, there is no reason to go higher then 2k. However... if you are working with square material, I highly suggest scanning at 2.5k or above, this way you have some wiggle room to zoom in and fill the wide screen frame if you want.

 

In terms of distribution 2k vs 4k. Considering the vast majority of theatrical releases are being finished in 2k today, it's pretty evident that 4k isn't important. A lot of older playback systems can't even accept the 4k material. So you'd have to make a 2k DCP anyway, so it really comes down to the added expense, is it worth it? If you telecine all the negative, cut your film digitally and use that original telecine for marketing purposes, someone buys the film, just tack on $50k to do a 4k deliverable.

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2.5K is optimistic, that's like saying that 35mm resolves 5K. Most tests I've seen show more like 3.5K detail for 35mm negative, which means that Super-16 resolves a bit less than 2K. But if you want to follow the rule that sampling should be twice the frequency rate, then 35mm should be scanned at 7K and Super-16 should be scanned at 3.5K. On the other hand, most real world detail doesn't create moire issues than higher sampling rates would avoid. A 2K scan of Super-16 is the same pixel pitch as a 4K scan of 35mm (and a 4K scan of Super-16 would be like scanning 35mm at 8K, which is considered excessive by most people.)

 

However, since there is more and more call for a 4K master, if you can scan and finish at 4K rather than taking a 2K master and bumping it up to 4K, you'd have better quality for 4K projection / distribution. But in terms of detail, mainly with a 4K scan of Super-16 you are capturing more of the smaller grains in the image but the actual image itself isn't going to look any sharper.

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Brian,

 

A 3.5K pin registered scan is going to give you the best image and grain structure for Super 16. Even for a 2K master.

 

Robert Houllahan at Cinelab is your contact.

 

Would you know it, I've used Cinelab since I started shooting film, way back in 2004. His lab will be doing the processing and transfer!

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Would you know it, I've used Cinelab since I started shooting film, way back in 2004. His lab will be doing the processing and transfer!

 

That's great, Brian. I am always very happy with their work.

 

Here is a couple of images from a film that I shot on Super 16, scanned in 3.5K and mastered in 1080p.

 

Sebastian.jpg

 

1.jpg

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Keep in mind that 4k S16mm is a diminishing return; yes it will be slightly sharper when shown in 4k or downsampled to 2k but you will not be going..."WOW!" like you might have between SD and HD/2K. If you have the budget, just weigh it against the cost of better lenses perhaps.

 

If it is a student project or low budget project, I would stick with a true 2k scan and put the money into lenses, lighting and set design. If it's a hit and Netflix wants it in 4k, you can always re-scan.

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We have actually recently upgraded our Xena Pin Registered machine to a Monochrome 5K Kodak 7.4u 14-bit sensor with the same extremely low noise and high dynamic range as the previous sensor so we are doing oversampled Super-16mm Sequential RGB scans at 4K for each channel now.

 

 

-Rob-

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  • 6 months later...

But in terms of detail, mainly with a 4K scan of Super-16 you are capturing more of the smaller grains in the image but the actual image itself isn't going to look any sharper.

Is this not often used as an argument not to scan 4K for(s)16? More grain is visible, which makes the image look harsher. Do you find that to be the case, David?

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But despite any argument against a 4k scan of S16 being worth while, the fact remains that more and more often you need a 4k deliverable. So as David has already stated, scanning at 4k now will look better than a 2k up-res. It will probably be cheaper than scanning at 2k and up-ressing later, you'd be paying someone to do that.

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I've scanned 4K and 2K on a Lasergraphics Director and compared them side by side on a large screen with a color calibrated projector. It looks basically the same - you would be hard pressed to find the difference. As has been mentioned here before, the main benefit is you future-proof the delivery and viewing. For example, TV through the 90s was 35mm or 16mm for SD delivery not bad, simply what was needed. We now consider even a DVD to be pretty low in resolution, and so many restorations are finishing in 4K. Yes, there is more detail and definition, but it really comes down to how you're delivering and plan to deliver in the foreseeable future.

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One camp says that 16mm really only has enough image information to warrant a 2K scan.

 

This camp is confused - it's mixing up optical resolution and digital resolution. They are different things, with different meanings entirely.

 

Optical resolution is about how much detail can be resolved (sharply represented) on the film. It's a function of the camera's transport, the quality of the lens, the focus of said lens, and the film stock being used. It's typically measured using line pairs in a test pattern. As line pairs get closer together, eventually they will appear to merge together. This is your optical resolution limit.

 

Digital resolution is two numbers: X and Y: Your horizontal and vertical pixel dimensions. Nothing more. That's it.

 

If you plan to project it at 4k, or show it on some other 4k digital media, the only logical option is to scan at that resolution (or higher, though that's not so easy to find), so that you avoid digitally scaling the image up. Whenever you scale an image up, you lose quality. You are making up image data that was not there before, and the upscale, no matter how good the algorithm, will always be softer than the same film scanned directly to that higher resolution. It's never really a problem to scale an image down, it'll look as sharp (or in some cases sharper) than the high res scan.

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