Film-Tech Forum ARCHIVE: The Cost of Creating a DCP of a Classic

This is topic The Cost of Creating a DCP of a Classic in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=16;t=001062

Posted by Lincoln Spector (Member # 6835) on 03-29-2012, 06:38 PM:

Hi, folks.

Assuming that a studio has a decent Blu-ray release of a classic film, and therefore, at least a 2k transfer, how difficult would it be to convert it to DCP?

Lincoln

Posted by Mitchell Dvoskin (Member # 751) on 03-29-2012, 06:52 PM:

As Blu-ray is only 1K, it is an assumption that a 2K scan exists. Although it would make sense to master at the higher resolution, the cost of scanning at 2K is higher than at 1080p, and we all know how short sighted the studios can be.

Posted by John Lasher (Member # 968) on 03-29-2012, 09:55 PM:

2k is a measurement of the horizontal resolution, not the vertical. If we go with your idea that BluRay is not 2k because its vertical resolution is 1080, then 2k isn't even 2k! Its vertical resolution is only 1080 for 1.85:1 and only 856 for scope.

BluRay's horizontal resolution is 1920, which is not quite 2k's 1998(flat) or 2048 (scope), but from what I understand, most catalog titles being released on BluRay are receiving at least 2k restorations to ready them for the format (in the cases where they haven't merely recycled an HD telecine done for DVD, or worse, broadcast.)

Posted by Antti Nayha (Member # 4980) on 03-30-2012, 02:34 AM:

quote: John Lasher
and only 856 for scope

858 to be exact [Wink]

The problem is that you will always need to do a little bit of scaling between 2K and 1080p:

1.85:1 ratio
1998x1080 (2K)
1920x1034 (1080p)

2.39:1 ratio
2048x858 (2K)
1920x803 (1080p)

And having to scale such a miniscule amount is always going to cost you some sharpness. So if you’ve made a 1080p scan, your 2K DCP will be compromised. Or vice versa; a 1080p Blu-Ray made from a 2K scan will be compromised.

This is why festivals etc. often get DCP’s with thin black bars around the image – these are made directly from a 1080p master without scaling. You win some sharpness over a 2K->1080p scaling job, but since such a format is not defined in the DCI spec, many (most?) projectors won’t have the appropriate macros ready to zoom out the black borders. So it’s either some extra work for the projections staff, or an ugly ”letterboxed” screening.

Ideally, everything would be scanned at 4K (or higher) and then downscaled exactly to the desired format. Scaling from eg. 4K to 1080p is much better quality-wise than scaling from 2K to 1080p.

Posted by Brad Miller (Member # 2) on 03-30-2012, 04:54 AM:

Click here

Posted by Antti Nayha (Member # 4980) on 03-30-2012, 06:56 AM:

I’ve also seen classic film DCP’s that were scanned from prints, instead of original camera negatives or IN/IP elements. That gives you exaggerated contrast, more jitter and grain and some scratches – but I’ve got to admit that I somehow liked the changeover cues. [Big Grin]

Posted by Mike Blakesley (Member # 26) on 03-30-2012, 01:16 PM:

I wish they would put changeover cues in modern movies' DCPs too. As a projectionist I think I just psychologically need to see the things, otherwise I start to get nervous every 15 minutes or so.

Posted by Lincoln Spector (Member # 6835) on 03-30-2012, 02:38 PM:

quote: Mike Blakesley
I wish they would put changeover cues in modern movies' DCPs too. As a projectionist I think I just psychologically need to see the things, otherwise I start to get nervous every 15 minutes or so.

Hmmm. Have to add changeover cues to my virtual "just like film" digital projector. So far I have:

* The DLP chips mounted on a very slight vibrator.
* Butterfly shutter mounted in from of the lens.
* Software algorithm to add virtual scratches. This can be set in years by age of "print".
* And now, cue marks every 15-20 minutes.

Lincoln

Posted by Carsten Kurz (Member # 5396) on 03-31-2012, 04:46 PM:

add a rattle sound mp3 player. Maybe one day they put that on ch16 of every DCP.

That brings up the idea of a 16/35/70/IMAX projector sound library. That way you could make your nasty DCI machine sound like your trusty old VIC5, Ernemann X, etc. Including those extra clatters around the reel changes.

Who's first?

- Carsten

Posted by Scott Norwood (Member # 30) on 03-31-2012, 05:51 PM:

I have posted some of these before, but here we go. These are all of a Century C 35mm projector on a Western Electric Universal Base, recorded in 2006.

projector running, door closed, film with splices
projector running, door open, film with splices
projector running, end of reel with Hatke reel-end alarm bells at 2:14; projector motor shuts down at end
Hatke reel-end alarm bell, projector not running (use this one to make the most annoying ringtone ever)

Edit and loop as needed.

Posted by Bobby Henderson (Member # 840) on 03-31-2012, 09:16 PM:

quote: Antti Nayha
The problem is that you will always need to do a little bit of scaling between 2K and 1080p

Unfortunately one of the issues taking place is the level where the scaling it taking place. It would be logical to assume Hollywood studios would be creating their 2K digital intermediates at 2048 pixel wide resolution. The reality is many "2K" digital intermediates are actually rendered in 1080p resolution and then slightly blown up to 2048 pixel width.

4K use is still fairly rare. Even in that regard care has to be taken with down-sampling a 4K image to a lower resolution target like 2K, 1080p, 720p, etc. to guard against issues of aliasing and moiré. The Dark Knight had IMAX imagery scanned at 8K and downsampled to 2K and/or 1080p. At least a couple shots had noticeable issues.