Film-Tech Forum ARCHIVE: Picture size issue with D-Cinema

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Posted by Thomas Pitt (Member # 4322) on 02-10-2010, 06:31 PM:

My local theater, the VUE Leeds Light, has recently installed RealD 3D systems in two of their screens. In both of these installations, the Victoria 5 has been removed and replaced with a Christie Digital projector and Real D polarizer.

In both of these screens, the picture seems too small when operating in 'flat' mode - there's a noticeable unprojected area on the left, top and right of the image.
When it switches over to 'scope' mode, the top masking drops, some lenses on the projector change, and the image now fills the scope area of the screen - including the parts that were unprojected before!

I'm not a D-Cinema installation technician, but I do wonder why this is happening. Could it have something to do with the top masking? (i.e. the image has to be off-center to allow the scope image to be full)

Oddly, the D-Cinema (2D only) projector in a third screen doesn't have this problem with scope format films!

Posted by Steve Guttag (Member # 268) on 02-10-2010, 07:12 PM:

It is all in the lenses. Christie was a late commer in the motorized lens game.

Hopefully, they have a suitable lens that covers both flat and scope ratios...on the 1.2" lenses it is possible to be on the edge of a range...the .98" ones have more overlap. Though there are many 1.2" lenses to try and cover the "between sizes."

You then have to contend with the fact that flat does not fill the width of the imager....1998 rather than 2048. Scope does not fill height 857 instead of 1080.

The other potential issue is again vintage related...if the projectors do not support full-frame triple flash...then one almost always needs another lens (shorter) to fill the same size screen since the EFIB board (can't do full-frame triple flash) do not, indeed, fill the regular image

The EFIB boards are based on a 1920 maximum width (rather than the imager's 2048 or the normal flat of 1998). So a flat Real-D image will be 1920x1038 and scope will be 1920x804.

Steve

Posted by Elise Brandt (Member # 5552) on 02-11-2010, 03:05 AM:

You mean to say there isn't an option for adjusting the lense settings in that projector? I don't know squat about any other than our projector but to me it makes no sense at all not to be able to adjust the settings, which would solve the problem in this case. Or have I misunderstood something here?

Posted by Steve Guttag (Member # 268) on 02-11-2010, 05:30 AM:

It would be a manual zoom...you physically move the zoom ring. But to have a single lens that can zoom between FLAT and SCOPE for both the 2D 2048 maximum width and the 3D 1920 maximum width is unlikely.

Again, if it is a manual system...they probably don't worry about the previews and just leave set for scope.

By the end of the series 1 projectors (2009) all new projectors had motorized zoom lenses. All of the Christie projectors had FFIB boards for full-frame triple flash.

Steve

Posted by Thomas Pitt (Member # 4322) on 02-13-2010, 11:07 AM:

There is no border on the bottom of the image - it's matched up perfectly with the masking. There IS a border on the other three edges of the image though. If you were to increase the picture size by zooming the lens, the bottom of the image would be on the masking.

I've seen 3D movies in these screens that are flat, and yes, the image does remain small and off-center. It's probably got nothing to do with the different sizes of 2D and 3D images, since the 2D preshow commercials and trailers are also affected by the small picture size.

If it is something to do with the top-only masking, surely there should be some way of adjusting the scope lens so that it projects a little bit downward (like with 35mm turrets). The flat lens could then be aligned and zoomed to fill the screen properly.

Posted by Steve Guttag (Member # 268) on 02-13-2010, 11:43 AM:

Actually...when running a mixed 2D/3D show (previews in 2D 3D feature)...the system is always in 3D mode...or you would have big brightness variances plus other complications.

The method of shifting an image varies too. There is physical lens shift and there is also "positioning" shift on the DMD itself. Those with Top only masking will often position shift the image down on the DMD for scope since it only has 804 on an EFIB or 857 on an FFIB thus there is room to move the image down.

If the scope feature looks right...I can almost guarantee you are seeing an artifact of how they centered the scope image for the feature and those not in the same format will fall where they fall on the screen. Again, with the current stuff (FFIB and motorized zooms/shifts)...this could be avoided but that was NOT always the case.

BTW...zoom is only symmetrical when the lens is centered on the imager...once it is shifted it will zoom about the LENS' virtual center, not the imager center.

Steve

Posted by Brendan Penny (Member # 5041) on 02-13-2010, 05:58 PM:

There are HEAPS of Christie's here in Australia that have been installed with manual zoom lenses. Why o why anyone would buy a projector that is unable to automatically change formats automatically is beyond me. Its like buying a 35mm with a single lens turret!

Anyway, the result is the same as you describe down here. Projector often fills the screen for feature o.k but pre-show is ran somewhere/anywhere on the screen often not filling it entirely. Mainly due to the projectionist not manually adjusting the zoom to suit the content aspect. Generally they set the lens to suit the feature aspect and just leave it.

I would say the Exhibitor either was on a tight budget or picked the cheapest quote without doing their homework.

So beware if you are buying a projector. Remember to ask if the lens is motorized!!

Posted by Demetris Thoupis (Member # 833) on 02-14-2010, 01:54 AM:

When having common width for both flat and scope a manual lens is money saving since you do not need to zoom almost at all for changing from flat to scope. The case is not the same if you have common heigh which usually needs scope to zoom more than the flat.
Demetris

Posted by Brendan Penny (Member # 5041) on 02-15-2010, 03:26 AM:

Most screens over here now are unfortunately constant width and there in lies the problem!! Bet you 'almost all' exhibitors don't bother moving the lens "almost at all" and invent a new aspect ratio!! Lets call it approxyvision!

I can only think of a handful of scenarios where you would not need a motorized lens. For a multiplex, there is no money saving way about it really. You either pay someone to stand there and adjust the lens manually or buy a motorized lens!

Or...not bother at all and go with approxyvision.

Posted by Steve Guttag (Member # 268) on 02-15-2010, 05:50 AM:

Just to be clear....until 2009...on a Christie projector...motorized lenses WAS NOT AN OPTION. Christie has since come up with a novel retrofit for their projectors. The existing lenses get snap-on rings to handle focus/zoom anthe lens mount gets changed to a motorized one. While Christie was first in all FFIB boards, first in all HDCP compliant projectors, seemingly the only one that offers all projectors with motorized lens mounts (anamorphic or WCL) and has stuck to the 1.2" imager for all but their smallest projector...they were last in motorized lenses. NEC was first in motorized lenses, then Barco, then Christie.

Whether you all want to believe it or not...this is STILL an emerging technology. You are going to see advances like this as the needs of the industry change. 3D was not high on the list until relatively recently...hence the whole EFIB/FFIB thing.

Steve

Posted by Brendan Penny (Member # 5041) on 02-15-2010, 04:59 PM:

I did not know that. So is it the MALM that is the retrofit add-on that you speak of?? How much does it cost, ballpark?

Posted by Steve Guttag (Member # 268) on 02-15-2010, 08:44 PM:

The MALM is for the Anamorphic or WCL lenses...not the lens shift or motorized zoom/focus.

Steve

Posted by Sonja O'Reilly (Member # 1322) on 02-17-2010, 01:14 PM:

Thomas, my old theatre had the same problem with our Christie and our tech told me to manually turn the knob (that's below the lens) to move the lens upwards (he said to never move the side-to-side without his permission, by the way). This took care of the image running over the bottom masking. Then you manually zoom the lens. We'd have to adjust it a bit to make it look good.
Edit: It's not really aproxyvision that way, as we can't change the aspect ratio, just the size of it. [Smile]

Posted by Brad Miller (Member # 2) on 02-19-2010, 01:45 AM:

quote: Thomas Pitt
There is no border on the bottom of the image - it's matched up perfectly with the masking. There IS a border on the other three edges of the image though. If you were to increase the picture size by zooming the lens, the bottom of the image would be on the masking.

Your installation techs suck. They should have never left the building until this and your other issue was done right, and they are tremendously easy fixes too.

Posted by Michael Brown (Member # 890) on 03-05-2010, 09:42 PM:

The studio's have pushed the 3-D phemomenon really agressively over the last few months, so cinemas have been forced to take it on. If you haven't got 3D you are old news, you can't show the latest nunber one blockbuster, the way that it's been marketed. Simple as.

So the head office of the multiplex roles out 3D installs to as many sites as it can. If they don't, all the customers will go some place else. So you have all these digital installs done in a rush, the quality could be better, but do you really have more time?

Posted by Demetris Thoupis (Member # 833) on 03-06-2010, 06:41 AM:

Actually its worth spending about 3 to 4 hours touching up on Masking, light, color correction and making sure all your damn Macros work perfect every time. Making a rush installation is NOT an option.
Demetris

Posted by Carey Barber (Member # 1586) on 04-10-2010, 10:00 AM:

I am having a similar problem, except it is 3D SCOPE that does not fill the screen.

The equipment is:
Barco DP3000 (about a year and a half old)
Doremi / DTS server
Real D 3D

When running 3D SCOPE there are black borders on all four sides. All other formats fill the screen fine -- 2D FLAT, 3D FLAT, and 2D SCOPE. The lens is zoomed out as far it can go.

We have one other D-Cinema projector, a Barco DP2000, that fills the screen with all formats.

What is going on here?!?! [Confused]

EDIT: I read about the EFIB boards and their limited resolution on this thread and elsewhere, but was not sure if that applied to my situation or not...

Posted by Elise Brandt (Member # 5552) on 04-10-2010, 10:55 AM:

I may be way off here, but I'm guessing the Barcos are all quite similar. Check if you 3D SCOPE and 2D SCOPE are using the same lense file. If they're not, change the 3D one to match the one you have on the 2D. Or just erase the lense file from that macro copletely, put on the 2D SCOPE and rewrite the macro using those settings.

I'm thinking it's always a bad thing to have the lense zoomed in or out as far as it can go, we did that and had all kinds of stuff go awry, like the dowser sticking and lamp not striking right... (yea that doesn't happen anymore, thanks to Mr, Siponen and his tweaking)

If I'm way off somewhere or just stating the obvious, I'm sure someone will let me know quite shortly.

Posted by Demetris Thoupis (Member # 833) on 04-10-2010, 01:22 PM:

Actually your DP3000 most probably does not support full frame tripple flash. If you are zoomed to the max and you cannot fill the image I recon the technician set it for tripple flash without resizing the image on the DMD chip to accomodate for the loss. You should call your check to come to change the 3D processing to double flash to be able to project the whole image. And yes the issue most probably is with the EFIB board. In triple flash on scope is not so much cut off as Flat on this generation of projectors.

Elise the lens files usually are different! Especially if you have a common height screen for both flat and scope. If you have a common width screen then you could get away with using the same lens file although that is not preferable.
Demetris

Posted by Elise Brandt (Member # 5552) on 04-11-2010, 06:02 AM:

Demetris; for example our 2D and 3D lense files are the same, go figure. Hey, I don't know why that is [Big Grin]

but I use what I see. I was thinking that might be the case here too; that they could use the other SCOPE file (that fills the screen) as a base for building a new setting for the 3D.

Out of curiosity; do you know if the 3D type used affects the outcome? RealD was mentioned here, we use Xpand. I don't think there is a difference between the two in this case but I don't know. I'm assuming you might [Big Grin]

(Edited: read it myself again and thought I really expressed myself badly. Tried again)

Had something else to ask in mind but it slipped my mind. Hmph.

Posted by Kris Verhanneman (Member # 5562) on 04-11-2010, 07:56 AM:

Elise, the only difference is when you use a DP3000 projector. Due to the fact that it is not full DMD in triple flash you need to zoom more in 3D than in 2D.

But somehow I'm not sure everybody installes the projectors the same way.

For the people who installe projectors on this forum, what would you prefer. Configuring to get the full screen (but using the outer limit of the lens) or leaving a small black edge on the screen (and not to use the limit of the lens)?

Posted by Demetris Thoupis (Member # 833) on 04-11-2010, 08:35 AM:

First of all it suck when you don't project the full image. Even when tripple flashing in 1st generation DP3000 units, you still LOOSE image. If you have the Dolby Masking files you can see that immediately. When tripple flashing you need to extremely resize the image on the chip to be able to get the full image projected (and then it means that you have to zoom to very extremes). Zooming is not prohibited. I think that Real D only works on tripple flash and not double flash like Dolby for example does (Dolby can work in both tripple 6:2 multiplication or double 4:2 multiplication). Elise, your Barco is 0.98'' chip and accepts full frame double or tripple flash. If you also have a common width screen (same width on scope and flat) you can get away with using the same lens file. I found that the masking files of the Dolby are the most reliable way to mask and resize and zoom. By the way, new generation DP3000 does support full frame tripple flash as well as 2nd generation 2K/4K upgradable units. Will 4K ever come into production nobody knows.
Demetris

Posted by Elise Brandt (Member # 5552) on 04-11-2010, 08:50 AM:

actually we have the same height for scope and flat, not width.

Wait -you're not talking about using the same file for flat and scope, are you? That's definitely not the case, just using the same file for scope and scope 3D. For some reason it works although I'm not sure it should.

Posted by Demetris Thoupis (Member # 833) on 04-11-2010, 09:48 AM:

Ok you confused me before. Lets state the obvious.
In standard cases you should use the same lens file for 2D scope or 3D scope.
You should use another file for 2D flat and 3D flat.
2 separate files. 1 for Flat and 1 for scope irrelevant of 2D or 3D content. This is the case when you use 0'98 chip which can use the full spectrum of the chip in all cases. When you use a 1.2'' chip which is configured as tripple flashed in 3D and cannot handle full frame (old generation) then you need 4 separate lens settings. 1 for 2D flat, 1 for 3D flat, 1 for 2D scope and 1 for 3D scope. If you use new engines which support full frame tripple flash on 1.2K chips then you should use the standard case, 2 files only, one for scope and one for flat irrelevant of 2D or 3D.
Hope that clears it.
Demetris

Posted by Elise Brandt (Member # 5552) on 04-11-2010, 10:00 AM:

Exactly. We're agreeing but I'm guessing it's my not-so-perfect choice of words that threw you off my meaning.

What I was wondering before is that if the 2D scope fills the screen but the 3D scope doesn't, using the same file n both might just fix the problem or at least allow some change. Or not! Half the time I think these machines won't think like they should...

Posted by Steve Guttag (Member # 268) on 04-11-2010, 12:44 PM:

I am unaware of ANY DP3000s that can do full frame triple flash.

Posted by Kris Verhanneman (Member # 5562) on 04-11-2010, 03:58 PM:

If some are able, how can you very that?

Posted by Demetris Thoupis (Member # 833) on 04-12-2010, 01:19 AM:

I know the OEM version now is capable for full frame tripple flash.
Demetris