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super 16mm - 2k / 4k scan, scanning area / overscan


Julian Fletcher

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Hi, have been researching a few of the film scanning companies out there, and a few of them are offering 2k and 4k film scanning of super 16mm.

I have found that at say 2k and certainly at 4k, the whole negative would get scanned (is this overscan?) - i.e. outer edges, sprocket holes etc - and therefore you would have crop the image out.

Does this mean that the image you are left with is not technically 2k (or 4k) resolution anymore? If so is it deemed to be an unacceptable practice when a company is advertising the scan to be 2k or 4k, and how do you ensure it does not happen? To be fair, have found this more so with the sorts of companies using scanners like a Fabriek Mueller HDS vs say a Spirit or Arriscan.

Would love to have your thoughts,

Best Regards,

Julian

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Scanners generally have an overscan on super 16 even with the proper optics. It's not a LOT of overscan, but it's edges for sure. This is to cover both the Super 16 format AND the Ultra 16 format + soundtrack. They'll do the same thing for 35mm as well, to get the soundtrack scanned as well. You can request from the person doing the scan that they give you just the image if you want.

Generally with super 16, you would need a 5k scan like the Scanstation (a very common scanner) to get a final 4k image. WIth a 4k spirit datacine, you can get a straight 4k scan which is really nice. I really like the Spirit because the imager is very nice and has extremely low noise floor. Where scanners like the scanstation, scanity and Xena are crisper over-all, the Spirit Datacine does a great job as well. The great thing about some of the more expensive scanners is their ability to stabilize off frame rather than perforation. So you'll have less wobble in the image, which is nice. The down side is the CMOS imagers noise floor is a lot higher, which can be seen in the blacks if the film wasn't exposed perfectly. I find the Spirit to deal with those issues in a much better way. 

The Fabriek Mueller HDS is kind of a toy compared to the other options. Remember, the Scan Station is around 90 - 120k to get into. The Spirit 4k, around 250k. So these are in another league really. 

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It depends entirely on the scanner, so you need to ask the service you're using. For example, on the ScanStation, Director, and many others, the entire optical system moves to maximize the amount of film that fills the sensor. On older scanners like the Northlight, the camera and lens are in a fixed position relative to the frame, so smaller gauges don't fill up as much of the sensor. 

You need to be clear with the scanning service about what you want. We bill by the size of the output file. So if you get a 4k file, but want it overscanned, your film frame is going to be smaller than 4k, because the output file size is 4k. You'd need to go up to a 4.5 or 5k scan if you want *both* overscanning and a film frame that's at 4k.

 

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Most of the "New" type scanners use a Color Bayer sensor camera like the JAI Spark 20000 in the Scan Station or the Ex-Kodak 16050 in our Xena and Kinetta. They allow for 2.5K or 5K Overscan but they are color camera systems and as such will have color "made" by math and some color separation issues especially with denser negative.

The Spirit 4K or Northlight or Ariiscan or Scannity or Director record each color channel separately (I.E. "True RGB") and some will offer overscan (Director, Xena 10K etc.) and True RGB but they get to be slower and more expensive. The Spirit 4K or Scannity or Arriscan have a more limited overscan ability.

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They allow for 2.5K or 5K Overscan but they are color camera systems and as such will have color "made" by math and some color separation issues especially with denser negative.

While this is technically true, we did some tests with our ScanStation in HDR mode vs our Northlight, and found that the ScanStation's picture quality is pretty much on par. The ScanStation is up to 14bit color in HDR mode, and the Northlight was actually noisier in the denser areas.

Again, I'm talking HDR here, in SDR everything you say about the bayer limitations and the noise are true. However,  it's also worth pointing out that if you do a Super2k SDR scan (an oversampled scan), you're basically overcoming the theoretical bayer limitations, and that, in the real world, they're not really limitations  unless you're doing some extreme pushing and pulling on the color. 

Edited by Perry Paolantonio
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10 minutes ago, David Mullen ASC said:

Would one advantage of a slightly overscanned Super-16 frame be the ability to apply image stabilization later?

I usually scan S16mm at 2048x1306 which shows some of the incomming and outgoing frame and allows for enough vertical overscan to fix most slight camera flutter without losing resolution. For "Full" overscan allot of times that is a creative choice to see more of the physicality of the film including the perf(s) and keycode etc. but for sure if there is a stability issue having the extra pixels helps to fix problems without losing resolution in the recorded picture area.

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11 minutes ago, David Mullen ASC said:

Would one advantage of a slightly overscanned Super-16 frame be the ability to apply image stabilization later?

In some cases maybe. We recommend Super 8 is overscanned. Because the frame is so bouncy in most cameras this gets you a frame line to grab onto if you want to stabilize. Regular 8 can be interesting if overscanned, because there's often picture between the perfs. For 16, S16, 35mm it's usually less useful. This is because those cameras tended to be so much more stable (at least the good ones), and the scanner is optically pin registered. So it's already as steady, if not more steady than a mechanical registration pin, on the scanner side. 

That said, I've seen some pretty bouncy images from different scanners so it depends on the machine you're scanning on too. 

Archives tend to like overscan so they're sure they get the whole frame. Mostly, though, it's a trendy look. Even when we crop inside the frame lines, you're getting more picture than you likely would have in most 16mm projectors...

 

 

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45 minutes ago, Perry Paolantonio said:

Again, I'm talking HDR here, in SDR everything you say about the bayer limitations and the noise are true. However,  it's also worth pointing out that if you do a Super2k SDR scan (an oversampled scan), you're basically overcoming the theoretical bayer limitation

I suppose then LaserGraphics can discontinue the trur RGB Director then... ?

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Just now, Robert Houllahan said:

I suppose then LaserGraphics can discontinue the trur RGB Director then... ?

I'm willing to bet they're selling a lot more scanstations. That said, there are other advantages to the Director (triple flash HDR, IR scanning, higher resolution, etc)

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