|
|
This topic comprises 2 pages: 1 2
|
|
Author
|
Topic: Whitaker Center in Harrisburg PA ordered to pay IMAX $366K
|
Marcel Birgelen
Film God
Posts: 3357
From: Maastricht, Limburg, Netherlands
Registered: Feb 2012
|
posted 02-24-2016 04:01 PM
quote: Leo Enticknap
Maybe the issue is that as large format converted to digital, the titles they wanted to show stopped being available in 15/70 film prints, and therefore Whitaker is arguing that a leasing contract signed in the belief that they would be throughout the contract term became unenforceable as the equipment became essentially obsolete before that term was up?
I think this is exactly the issue at hand. There were quite some 15/70 releases of Hollywood blockbusters up until they started with their IMAX digital LPF concept. So, IMAX probably proposed to "upgrade" to their digital system, but since this upgrade costs serious money, they wanted more commitments, as in, more kickback yielding Hollywood productions being shown, which didn't fit into their daily operations.
quote: Ari Leedsw
Isn't that simple math? Assuming parity elsewhere, 2x2K projectors is half the resolution of 4K. That's assuming the same aspect and 2,048 lines and 4,096 lines, respectively.
The IMAX Digital (Xenon) system overlays two images over each other, it's adding brightness and not really any resolution. Also, the Christie 2230 is a 2K system, not a 4K system.
| IP: Logged
|
|
|
|
|
|
|
|
Marcel Birgelen
Film God
Posts: 3357
From: Maastricht, Limburg, Netherlands
Registered: Feb 2012
|
posted 02-25-2016 03:49 PM
There have been many discussions about how the IMAX Digital system works. The short answer is: You're not supposed to know, it's their secret sauce, their black box. What we do know is that their DCPs differ from the "mainstream" DCPs, but we also know that most of the content is just 2K in resolution.
The IMAX Digital Xenon system is a different setup than the IMAX laser setup. Whereas the Xenon system uses a mix of 2K and 4K projectors, the input is always 2K. The laser system s is a full 4K system.
In 2D mode, one of the images seems to be out of focus, while the other one seems to be clearly in focus, showing a distinctive pixel grid.
So, the trick here doesn't seem to be to get any extra resolution by projecting two overlapping pictures, which would be close to impossible, the aim is to increase brightness, contrast and hide the underlying pixel grid.
In 3D mode, both projectors seem to shift slightly out of focus, but you will notice the pixel grid better while in 3D mode.
How big the pixels actually are on an oversized IMAX Digital screen is clearly visible if you're watching a show with subtitles. For whatever reason, the anti-aliasing of their subtitle engine seems to be broken, often resulting in very sharp and ugly edges.
Please notice that some of the above is speculative and has been derived from the limited tests I could do on their Digital Xenon system. Maybe the system was faulty and this lead to the wrong conclusions.
| IP: Logged
|
|
|
|
|
|
Steve Kraus
Film God
Posts: 4094
From: Chicago, IL, USA
Registered: May 2000
|
posted 03-21-2016 01:30 PM
I would have expected that the 2D system shifts the pixel grid by 1/2 pixel both horizontally and vertically, thus concealing the grid. What they do in their black box and with different DCP data I do not know. 3D would just be 2 projector 3D that anyone presumably can do.
As for the prior discussion of film resolution, you should take any discussion of pixel count with a grain (ahem) of salt. As has been said, there is no particular number. It's a graph called a modulation transfer function and it relates resolution (in line pairs, not pixels) to contrast. The simplest explanation is this: You look at test film under a microscope and try to distinguish alternating black and clear line pairs. As they get finer and finer they disappear into the grain. Rather than one person saying it goes this far and another person saying well, I think I can still distinguish them at this higher level, it's presented as a graph, line pairs vs. contrast levels.
Called a function because it's a relation between two things. The negative has an MTF, the positive has one, the printing method gets involved as do lenses. With film you can do it per linear distance across the film or for the image as a whole.
Bottom line is that you have an image that is the result of a cascading chain of MTF's for the film stocks, camera and projection lenses, printing processes and on and on resulting in what you see on the screen.
| IP: Logged
|
|
Carsten Kurz
Film God
Posts: 4340
From: Cologne, NRW, Germany
Registered: Aug 2009
|
posted 03-28-2016 05:13 PM
Jonathan - what I heard is that IMAX laser DCPs (features) are all 4k, that is, IMAX own mastering uprezzes everything to 4k, no matter what the source format/resolution was.
Some call it uprezz, some call it DMR - whatever...
On the laser shows I saw, there was huge differences in image quality between different trailers, IMAX brand clips, and the main feature. Of course, the screen size/viewing angle alone will make differences between footage much more obvious than on standard size screens.
- Carsten
| IP: Logged
|
|
Marcel Birgelen
Film God
Posts: 3357
From: Maastricht, Limburg, Netherlands
Registered: Feb 2012
|
posted 03-28-2016 05:44 PM
quote: Steve Kraus
I would have expected that the 2D system shifts the pixel grid by 1/2 pixel both horizontally and vertically, thus concealing the grid. What they do in their black box and with different DCP data I do not know. 3D would just be 2 projector 3D that anyone presumably can do.
The black box has two Nvidia GPU cards in them. They use them for real-time image manipulation.
Shifting the grid half a pixel horizontally and vertically is hard to do. The projectors are side-by-side and housed in bulky enclosures. With the lens openings this far apart, you'll have noticeable different geometries on screen. Some of which can be slightly corrected using lens shifting, but not all of them can.
The Christie Duo system offers a mirror-based setup that puts both lenses much closer together, which achieves a better on-screen convergence.
You could try to digitally deform both images to perfectly match over each other and it will probably work to a certain extend. But, you will lose a lot of image quality by doing this. Even worse, you might introduce some new and disturbing digital artifacts.
So, what would be the best solution? You leave one image mostly as it was, at least you're not going to move around pixels in this one as to not lose any resolution. That's your "sharp image".
Now, you've got this other projector at you disposal. On this, you're going to project an image which is slightly blurred. Since it will be already slightly blurred, if you need to perform some manipulations to fit it onto the other image, you're going to do it on this one. This image will be your "soft" image, which will primarily function as contrast enhancement for the sharp image. It will not only improve the contrast of the image, but it will also help to get rid of the visible pixel grid a great deal.
Please notice: I'm pretty sure this is the essential part of the so called Digital (Xenon) IMAX Image Enhancement magic. They will not acknowledge this, neither can I acknowledge anything. I'm probably talking out of one of my bodily openings, I let you decide if it's the correct one. They might use actual fairy dust or Horn shavings, from Unicorns, imported from Alpha Centauri.
| IP: Logged
|
|
|
|
|
|
|
|
|
|
All times are Central (GMT -6:00)
|
This topic comprises 2 pages: 1 2
|
Powered by Infopop Corporation
UBB.classicTM
6.3.1.2
The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion
and agrees to release the authors from any and all liability.
|
Home
Printer-friendly view of this topic