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Old March 8 2013, 12:00 AM   #2014
Maxwell Everett
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Re: Season TWO OFFICIAL TNG Blu-Ray Discussion Thread

Yeah, I think both CBS Digital and HTV's separate working practices may have combined to make that shot of Troi entering the bridge in "Samaritan Snare" and the one in "The Child" look overly soft. What they really should have done is scan all those anamorphic shots at 4K. That would have given them more than enough resolution to play with to do the digital pan.

Unfortunately though, CBS Digital doesn't own a 4K scanner. CBS Digital owns a pair of (obsolete but still good) Spirit 2K DataCine film scanners -- so right off the bat all the film elements are being scanned at a resolution of 2048 x 1556 -- usually this is more than good enough for Blu-ray. (HTV can do 4K scanning according to their website... but I don't think CBS was interested in paying for that.)




The area they scan is called the Full Camera Aperture and it represents the maximum image area available on the 4-perf 35mm color negative film. Normally for the show, they use what's known as the TV Transmitted Area, which in 2K would be an area about 1600 x 1200 within that 2048 x 1556. This is then essentially downconverted to 1440 x 1080 (1.33:1, 4:3) -- or in the case of HTV's work in S2, 1458 x 1080 (1.35:1). For "Sins of the Father" CBS Digital apparently cropped most shots directly to 1440 x 1080 (no downconverstion).

And actually it's a bit more complicated than that as they are actually editing the show with as much available image area possible left and right of that TV area within a 1920 x 1080 (1.78:1, 16:9) frame (see here). They then hard matte the video with black pillar bars on the sides for Blu-ray. HTV obviously gave us slightly more than they were supposed to, resulting in VFX elements that disappear before they reach the edge of the visible frame.

As Mott says, for this particular shot in "Samaritan Snare" they used 2x anamorphic Panavision lenses (aka CinemaScope). The anamorphic aperture is actually a slightly smaller subset of the full camera aperture (just like TV Trans.) and its corresponding resolution in 2K is 1828 x 1556 (1.17:1) -- so it has the same image height but is a bit narrower horizontally.

Now here's what I *think* happened next: In order to correct the 2x anamorphic squeeze, they changed the scanned footage pixel proportions to 1828 x 778 (2.35:1) instead of scanning it at or scaling it up to 3656 x 1556. Notice that at 778 lines it now has less vertical resolution than the typical footage scanned and used for the show at 1080p? In fact, it only has about 72% of the vertical pixels of 1080p!

HTV then took that footage and DNR'd it to wipe away all that pesky grain and did the intended viewscreen composite and digital pan across the frame from left to right (the available TV area at this point would be 1035 x 778). This pan also has added motion blur to simulate a real-world panned shot at 24 frames per second with a shutter speed of 1/48th of a second. That, of course, softens it even more.

Then, the finished shot would have been upconverted back up to 1458 x 1080. But again, disclaimer here: I'm not saying that I know this is what happened, it's just my pet hypothesis.
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Last edited by Maxwell Everett; March 8 2013 at 01:15 AM. Reason: Added HTV 4K info
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