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Spirit 4K DataCine Scan Question


Frank Chang

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We did a scan with Spirit 4K DataCine into DPX 16 bits. The scan quality is perfect and we plan to have more reels to be scanned.

The only question is that the scan does have approx 2% to maybe 5% on the right side of the image that is not in the scan dpx. Is this

normal (i.e. for the 2% to 5%) for the fit-to-image option (without going to over-scan)? Or are there better scanner that can really

scan all the way up to edge to edge without overscan and does not show the frameline/borderline?

Edited by Frank Chang
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I believe with the likes of the Director at MetroPost, the Xenia at Cinelab, or the ScanStation at Gamma Ray Digital you can adjust the zoom on the frame to catch as little or as much of the frame lines as you want.

 

However, the frame itself may not be exactly a 4K aspect ratio. What format is the film? If the aspect ratio of the frame on the film doesn't match the scan aspect ratio there is no way to avoid cropping something to make it all fit without seeing the frame lines in an "overscan".

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https://www.theasc.com/magazine/april05/conundrum2/page3.html

 

This article suggests it's a fixed relation so Academy width gets scanned at 3656 pixels, Super at 4096.

 

 

Yeah. The more modern systems are capable of zooming in or out or centering however you wish, with cropping of course. It sounds like the spirit is probably centered for super35 so it ends up off center for standard 35mm. Unfortunate.

 

I would do a 5K scan at Gamma Ray or Cinelab with frame overscan so you can crop and frame however you wish, even scene to scene.

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The DPX file property in Photoshop does show 4096 x 3112 at 72 dpi.

 

Here is a sample attachment of a frame. Notice the top of the image have curves on both corners.

If doing the overscan, I assume the curves will have to be edit-out anyway.

 

Upon closeup checkup, the scan does appear to be cutting off on right and left at the curve.

post-70778-0-42368900-1474139440_thumb.jpg

Edited by Frank Chang
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The soundtrack area is usually on the left, but maybe this is upside down... This isn't a scan, right? Otherwise why is it crooked? Maybe they've been scanning it flipped but using Academy width so that they are scanning most of the soundtrack area but are cropping the right side of the image?

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Oh, sorry, yes, this is just a photo sample took from a cell phone camera upside down. The scanned image is not crooked. There are no soundtrack on the film.

The photo is only to show about the 4 corners with the curves. The blank area on the right of the photo is suppose to be on the left

and where the soundtrack area is suppose to be.

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Just to avoid confusion. The photo above is an image took directly from the frame of the film with a cell phone upside down. It is just to show the frame image with 4 corners with the curves.

The DPX scanned images are perfect and not crooked, except the left and right are cut-off at the curves. I suppose any overscan will show the curves and will have to be edit-out anyway?

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Just remember that the three linear CCD's in a Spirit 2K/4k are fixed as is the film gate slit and lens, any scaling is done in hardware not optically.

 

The Spirit 2K/4K has the advantage of scanning each film record in 4096 lines i.e. R,G and B so no Bayer mask interpretation so these scanners produce a high speed true RGB scan.

 

Compare this to our Xena Pin Registered 5K scanner, which uses a 5K monochrome sensor and sequential scans of 5K for each R,G,B and a moveable lens and CCD Camera, this allows for overscan etc. but the speed is the tradeoff at 2Sec per frame instead of 5-10 FPS for a Spirit 4K.

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Keep in mind the difference between camera aperture and projector aperture. During shooting he negative will be carefully framed to the projector aperture, if you show more than this, you may run into dollytracks, microphones, etc. The director and camera operator are not going to like it if you show unintended extra image. Unless it is your own film, it is best to stick to the official formats.

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Thank you, David.

 

Robert, with the speed of Xena (slow) vs Spirit 4K, is there a scan image quality difference on the DPX?

(Assuming that the overscan of 5K still gets edit-out back to 4K)

 

Dirt, we are in the process of doing archival and restoration for the owner.

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https://www.theasc.com/magazine/april05/conundrum2/page3.html

 

This article suggests it's a fixed relation so Academy width gets scanned at 3656 pixels, Super at 4096.

 

 

Our Northlight works like this - Academy is 3656, Super is 4096 (at 4k. It can scan up to 6k).

 

The ScanStation, and I presume the Xena, as well as most modern scanners, have more flexibility. On our ScanStation, the sensor itself is about 5.1k, but it's always overscanning so that it can do optical pin registration before writing the files to disk. That means your actual frame area is 4k and that lets the operator specify the amount of overscan to dial in exactly what the client wants.

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So, if Photoshop is showing the DPX image property as 4096 x 3112 at 72 dpi. Does this still means the

actual scan is still 3656 (academy format, up-res to 4096) and not actually 4096? If so, are we getting

a lessor quality 4K DPX image file?

 

The scanned image does cut-off left and right at the start of the the curve, which is fine for us as those

areas were never meant to be shown.

Edited by Frank Chang
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I wouldn't get too worked up over the difference between 3656 and 4096, the same thing happens with 2K scans, and something similar happens with 2K DCP's -- 1.85 movies are 1998 pixels across and 2.40 movies are 2046 across. For a 4K DCP, 1.85 movies are 3996 across and 2.40 movies are 4096 pixels. I'm sure a 1.37 Academy movie in a DCP package would use maximum height and even fewer pixels across than 1.85, since that also uses maximum height.

 

But as for how your DPX file ended up being 4096 for an Academy width, you really should be asking your post facility.

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The Spirit 4k should not have any problem to capture a complete Super 35mm image. Under the Sizing Data tab on the Spirit 4k panel, are controls for zoom, pan, and tilt. I would suggest trying these. In CCD "test" mode, the 4k can capture 4112 pixels, though I've never seen anyone use this mode for production work. No pixels should be getting cut off on the edges. The Spirit 4k User manual has charts that detail the various format sizes.

The Scanity film scanner native resolution is 4300 pixels, so It is also capable of overscan like the Xena, Director, or Scan Station.

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Thanks, Craig. So, I assume you mean the Spirit 4K is not fixed lens with limits on Academy 1.37 scan at 3696

and users should be able use the sizing data tab to select the scanning area to produce true 4096 scan for the

selected area, regardless if it is super 35 or academy 1.37?

 

I will check out the manual.

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One of the PDF's says "Real-time scaling engine for sizing and positioning up to 4K output resolutions and for converting 4K scans to 2K (digital oversampling)"

 

So it sounds more like even if the scanning array is fixed in relation to the film, so that Academy area is scanned at 3656 pixels, the scaling engine can make this into 4096 pixels.

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