BluRay vs DCP Aspect Ratios

[Ryan Gallagher]

In commenting about our setup. I realize there might be a smarter way to tackle ALT Blu-Ray sources and get them to share the same sizing on screen (masking etc) as the DCP equivalent ratios? Without resorting to alternate zoom/ILS and screen files?

For example, is it possible to tell a Christie Series 2 to use a source file that represents Blu-Ray Scope (1920x803), but have it scaled and projected equivalent to a DCP scope (2048x858)?

In most of the configuration I've revisited, I've used an ALT source file that matches the DVI signal source, not a fraction that represents the contained aspect ratio. But predecessors in this booth have taken the other approach, there are tons of specific source files populated for various ratios.

What would be the "standard" approach to this?

[James Gardiner]

Sorry, there is no way of getting out of having to setup different channels/masking setting.

You do not want to use any form of image manipulation as if you did, you're doing a small interpolation from say, 1920 to 1998 wide. Doing so would introduce a significant blurring of the image. If doing a large interpolation, it is not so apparent. In general, best to let pixel for pixel map into the DMD to ensure a crisp image. You are best to zoom/mast the image or, as is mostly done, just less there be black areas of the image fitting into a Scope or Flat channel on the projector.

You cannot rely on the aspect coming in from a BluRay as well.
Unless you have the time to check and custom set for every ALT content show coming in. Best to keep it as simple as possible. (IMHO)

[Ryan Gallagher]

That was kinda my instinct (re DCI ideals and square unmodified pixels), hence why I did them all this way, but as ALT is not nearly as strict when it comes to pixel manipulation, figured I’d ask if anyone does it that other way.

And honestly I’m still not sure it would even permit such a configuration.

you are definitely correct about it being hard to check image area resolutions/aspects on blu ray. Case labels and internet knowledge of intended ratios only get you so far. I added X and Y stripes of artist tape to the bezels of our preview monitor, and have relevant tick marks on it for the common ratios.

[Steve Guttag]

The vast majority (and I mean 99%) of my installations have taken the scaling approach, not lens zooming. And, you know what James, not a single complaint or even a question as to if it was scaled or zoomed (and these have been in some pretty critically judged places).

Yes, all S2 projectors can do it as the ICP is a scaler unto itself. The blurring in a moving image is, pretty much, imperceptible versus in a static image or the other artifacts visible in the typical Blu-ray (or worse, DVD) transfers, when magnified.

Using an 1920x803 (or 1920x804) input file will scale up to a 2048x858 or 4096x1716 just fine and likewise on 1.85 ratios. Depending on the installation, you might not have the range left in your lens to zoom out to the 1920 formats.

Of the S3 and S4 projectors that are using OEM based ICPs, I have been able to use the ICP-D (Barco) though it does require different input parameters as it centers differently and on the Sharp/NEC, which they call S2 still but S3 denotes that the ICP functionality is not TI made. So, for example, the NC-3541L.

Because of the drift all of the projectors go through with lens movement (they are not all equal and the smaller the DMD, the worse they get), I try to minimize lens movements with fixed lens being best. I just installed a screening room with a Christie CP4415-RGB and that lens is set to never move. They have 4-way masking so there is no reason to zoom or scale.

For every lens setting resulting in a change in zoom, that necessitates a separate calibration for light level too. It makes accommodating an ever growing list of aspect ratios progressively labor intensive to support. On new installations, with constant height screens, we configure for F-133, F-166, F-178, F, F-200, F-220, S-220 and S. By and large, that means four lens presets and mating light calibrations (Flat, Scope, F-200 and F-220).

[Agnius Acus]

I use separate presets for different kinds of resolutions, although for external sources it is plain 1920x1080 with black bars on both sides of our FLAT format screen. I use it for presentations only, where no parts of the image can’t be cut. It’s been ages since I screened anything directly from the disc.

[Steve Guttag]

Naturally, for PC presentations, particularly with a native 16x9, it is 1920x1080 with no scaling using the same lens preset as Flat but with a suitable screen file though, for laptop stuff, I don't always do that as you'll start clipping taskbar stuff or other parts that the presenter may find essential. I, also, if the system can handle it, will have a separate light calibration for those too so that they can have a higher ambient light level with a snappy Power Point type show.

[Leo Enticknap]

When doing Q-Sys installs in university lecture theaters and other mixed use venues, I usually put UI buttons for "Light level - cinema" and "Light level - lecture/presentation" (or some such wording, usually guided by the customer) that triggers a separate light file in the projector (14ft-l CLO for cinema, and usually 90% power for lecture), but doesn't change anything else. I was first asked for this a few years ago, but have been adding it to my designs ever since, as it seems like an obvious requirement for these places.

[Ryan Gallagher]

This turned into a fruitful discussion after all. Thanks Steve and all. I guess there are indeed multiple ways with their respective tradeoffs to skin this cat. I'll give the source-file ICP scaling method a burl and look at the relevant compromises. It may start to better explain that screen file "letterbox" setting that often seems superfluous, but things look very wrong when unchecked.

Yet another way, if I was more inclined to rip Blu-Rays, would be to do the cropping and scaling when making a DCP version. I should really tool up that option if for no other reason than reliability.

All are correct on ALT 1080p "presentations", we also use a separate no-crop screen file for that, cause slides often utilize the image and title safe areas, or just have boxy type border decorations that look ridiculous when cropped for our keystone. I'm really just discussing presenting films via ALT sources.

Light file variation is a very good point on the zooming method. We have not been in the habit of using anything other than the relevant FLAT or SCOPE light file for our alternates. Although "MOST" alternates do fall on the flat or scope zoom marks... some do not however such as F220 and S220, or minor deviations with letterboxed 1080p blu-ray films, or our 35mm/70mm backup sizing. As is, we were fairly under-spec'd for our projector/lamp combo to begin with. We just barely crest 14fL on a good day with a new lamp in scope (14.5fL when checked last week by a studio tech and a 15 hour lamp). Brightness only ever gets checked when techs are in with festivals. And all they ever ask for is more brightness or check that we are indeed 100% on the lamp/light file. We don't run light-LOC etc, just leave it at full. Studio techs are usually happy, but that is probably cause we throw a new lamp in before those events.

I suppose if I wasn't so pegged near our brightness limit for everything, I would have to be more careful with alternate zoom approach and light levels. It would not surprise me if when measured our current flat light file is a bit bright on a new lamp, cause the studios always ask us to run at full.

The less our lens would have to move the better for sure, as there is sometimes drift. Though we often have to touch ILS settings anyway because the screen is flown, not permanent, and depending on air currents may land slightly closer or further. I should really tag some nails into the deck as leg spike marks, so we can just nudge the bottom it into the same position every time.

Speaking of trying to avoid lens moves. I find that even with the exact same lens-shift numbers in the ILS file, the lens will often still make it's direction calibration move to get there between format changes. Is there some trick to saving the ILS file making sure that you are approaching the number from the same direction in both ILS files that avoids this?

EDIT: perhaps it was a dumb question. Just use the same ILS file if they are truly identical of course! But because of our approach I was in the habit making an ILS file for every format, regardless, mostly so that when you are in a hurry with creatives and you have to change something, you are not impacting every format that borrows the same ILS. One does not always perceive having the time within tech-checks to do it properly and copy out files and adjust channel to the new screening specific ones.

Although we do have the necessary masking to do it, i'm not really a fan of just having a reduced picture size when showing wide aspect films from a Blu-Ray, always aiming for maximal use of available screen. So it seems like either what we are doing, or Steve's approach of letting the ICP upscale to match the DCP sizing.

If I was showing a DVD off a DVD player (and not a blu-ray player that can pixel double itself), we'd certainly do not have enough zoom range for the zoom. So yeah, this source file ICP scaled approach definitely has situations where it would be the REQUIRED approach.

[Ryan Gallagher]

And no, we don't show DVD films anymore, but there are occasions where that is the only gettable option for a digital backup for a 35mm screening. So I still have to pretend like I might have to show them.

[Steve Guttag]

In general, disc based shows, for our clients, tend to be 1-offs where the time to rip to DCP would be inefficient or not covered in a rental agreement where the theatre may be rented for a birthday party sort of thing The theatre won't have anything to do with the movie beyond providing the room and projection/sound equipment (the client brings their own source material).

Disc based shows are always more tricky and apt to glitch while being perfect during any run-throughs.

We still put in a fair number of Blu-ray systems though and they do get used though not constantly. In fact, one of the things I've been promoting for my Q-SYS systems is the concept of not buying replication of equipment just so you have it if the right sort of use might happen along. That is, if you have say 10-screens, what is your worst case scenario of needing a Blu-ray (or laptop port, for that matter)? 1-2 screens at a time? Fine, get 3 systems so you have a spare (you don't want to dump a rental due to equipment failure). Then, let the system configure itself based on the use case (send the blu-ray to the theatre being used or plug in a lectern in the theatre being used). But don't hang $1000s of dollars of equipment/wall plates or disc players in EVERY theatre on the off chance it might be used or tie yourself to only using these 1 or 2 screens. Using various AV over IT solutions, like Visionary Solutions (and there are many others, including Q-SYS' NV series) allow you to install cheap CAT6 or dark fiber and then only plug in the expensive pieces where you need them for the particular event.

Control systems like Q-SYS can also allow one to have a degree of a professional show even with a Blu-ray player (it also depends on the player). We've been using the Tascam BD-MP1/BD-MP4K. For instance, configuring a credit start/show end, just like on a DCP so you don't have to baby the show.

In the case of DVDs, normally, now the Blu-ray player takes care of scaling them up to the player's native output. However, I do have some sites where we have created "Standard Definition" projector presets to deal with 480 based stuff, including anamorphic squeeze content though that is really becoming the odd-ball. People have become so accustomed to HD that seeing SD now is a shock as to how rough it is when blown up to a big screen.

[Ryan Gallagher]

In general, disc based shows, for our clients, tend to be 1-offs where the time to rip to DCP would be inefficient or not covered in a rental agreement where the theatre may be rented for a birthday party sort of thing The theatre won't have anything to do with the movie beyond providing the room and projection/sound equipment (the client brings their own source material).

Yeah even for us, time to make a DCP from a Blu-Ray would mostly be me volunteering time at home if the disc showed up without permissible booth overlap time before the screening event. In a rental context often the disc shows up with the clients day of, thankfully we don't do many of those. Our summer film series is the only place I would realistically have time to do that kind of DCP prep, and the booth lacks a suitable workstation for that kind of longer DCP authoring (though one has been requested). So the player hardware and associated projector configurations is still required.

We still put in a fair number of Blu-ray systems though and they do get used though not constantly. In fact, one of the things I've been promoting for my Q-SYS systems is the concept of not buying replication of equipment just so you have it if the right sort of use might happen along. That is, if you have say 10-screens, what is your worst case scenario of needing a Blu-ray (or laptop port, for that matter)? 1-2 screens at a time? Fine, get 3 systems so you have a spare (you don't want to dump a rental due to equipment failure). Then, let the system configure itself based on the use case (send the blu-ray to the theatre being used or plug in a lectern in the theatre being used). But don't hang $1000s of dollars of equipment/wall plates or disc players in EVERY theatre on the off chance it might be used or tie yourself to only using these 1 or 2 screens. Using various AV over IT solutions, like Visionary Solutions (and there are many others, including Q-SYS' NV series) allow you to install cheap CAT6 or dark fiber and then only plug in the expensive pieces where you need them for the particular event.

And YES on the non-duplication, instead relying on more flexibility in infrastructure. Between our two spaces, we only have one 4K Ultra capable player that floats for example, unfortunately it was a non-ideal non-automation friendly model purchased in an emergency. Dry-lines are our friend although fiber and Video over IP is not in the production mix yet. Coming from a theatre and not cinema-chain background flexibility is the name of the game. We are less likely to have fancy new things like video over IP that is exposed for event use (but might exist at the building level for lobby/dressing-room monitoring etc), but do have SDI, XLR, and Ethernet dry-lines all over as a convenient alternative to running long cables.

I gather these shared resources are programmatically routed using QSYS, and you are not promoting carrying a blu-ray player from rack to rack etc. ;-) (Like we do for the rare occasion we need to read a 4K Blu-ray between our two spaces). LOL Other theatrical spaces I work in town at least have a booth SDI matrix switcher for their video routing. We are a bit shoestring here, all our SDI dry-lines converge in the trough at the balcony rail. I can hard patch any to any based on the show's needs. More walking involved, but perhaps more flexible with less cable pulling than a matrix switcher would have required. Works for us, but definitely could use improvement. The one gotchya for us is no re-patching mid-show. Patch point is out in the audience! Whoops.

[Steve Guttag]

We can work it either way. Carry the Blu-ray to the theatre, plug it in with a shorter HDMI cable and plug in an Ethernet cable so it can be controlled. Alternately, have a Central area that houses the available A/V equipment and plug in a "Decoder" at the desired theatre that will have the HDMI output to the projector. Q-SYS (and Visionary Solutions) does care where the unit physically is. Put a big label "A" on the Decoder and the Blu-ray player. Then, it is a simple matter of, from the theatre you are going to use, choosing the Blu-ray you want to control and the Decoder you are plugging in and that, effectively makes the route (the self-configure part of AV over IT).

Q-SYS can make some aspects even easier by using what they call "Dynamic Pairing" such that when a known device is plugged into a specific Ethernet port, it will self-configure to assign that device to that location for as long as it is plugged in. This is handy for being able to move a lectern around so if you wheel it from theatre 1 to theatre 2, when the system sees it plugged into theatre #2, it routes its microphone and laptop...etc to theatre Film-Tech Cinema Systems

[Carsten Kurz]

We do have a few custom presets on your Sony to deal with realtime Bluray showings that also adjust our side masking. But in general, I convert most Blurays to DCPs now and try to achieve a standard flat or scope AR whenever possible. I guess the issue is, do you need standard procedures for a range of staff that is not competent for all possible adjustments, or are you on your own with these things and know all the bits and pieces towards a perfect AR adjustment. It doesn't get easier with the range of new aspect ratios we see in recent years.

[Ryan Gallagher]

We do have a few custom presets on your Sony to deal with realtime Bluray showings that also adjust our side masking. But in general, I convert most Blurays to DCPs now and try to achieve a standard flat or scope AR whenever possible. I guess the issue is, do you need standard procedures for a range of staff that is not competent for all possible adjustments, or are you on your own with these things and know all the bits and pieces towards a perfect AR adjustment. It doesn't get easier with the range of new aspect ratios we see in recent years.

Yeah if it was always just me I would not be aiming for having everything as pre-configured, but we have two others that can often cover films for scheduling and keeping overtime from getting excessive. They are far less comfortable making projector adjustments when needed, and if they do make them, they are more likely to overwrite something that is needed in the base set of formats. Considering our screen is only in for film events, it makes restoring or checking things on screen quite difficult until the next film.

[Tony Bandiera Jr]

At one University Screening room I designed and built (not the one in the Warehouse) I had a joggable bottom masking and full motion side maskings to help out with oddball DVD/Alt content ratios. The bottom mask was defaulted to full open for all film formats and moved for anything other than 1:85 and 2:39 in 35mm and 1:33 in 16mm. I don;t recall ever setting up lenses or plates for 1:66 or 1:37 in 35mm in that room...I'd have to dig up my paperwork to see what I included.

The very best setup is full 4 way movable maskings, but the rigging and expense is considerable. My colleague and I did that for the AMPAS screening room with 20(!) presets accessible for EACH masking panel. I still have the as-built spreadsheet for the control wiring and AXM relay cards assignments.