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Author Topic: Ghosts of the Abyss in 35mm 3D? Ken McFall Jedi Master Film Handler Posts: 615 From: Haringey, London. Registered: Apr 2001 posted 04-20-2003 10:11 AM                     May not fit here exactly but here goes. Went to see GOTA at London Waterloo Imax yesterday and enjoyed the film itself. However, its been a while since I've seen an IMAX 3D show and I have to say I was not impressed. The last time I saw a show we had to wear electronic headsets and the 3D was amazing as was the image quality. Yesterday we were given flimsy glasses that used poloarising filters and the image was very dissapointing to say the least. At times there was a distinct ghost image, presumably the filters not cancelling out wrong eye information. Also the focus was very suspect and the image seemed to stutter as things moved quite fast, mainly peripheral but disturbing none the less. The light fall off from left to right was noticable but not too bad. We were sitting to the left off center. I did not see any of this on my last visit. I relaise the expence of using the electronic head gear must have been considerable, cleaning and charging etc etc. Also there may have been some resistance from the public to wearing them. But for a quality experience it was unbeatable. Why the change to this simpler, cheaper system. The impact is still there but its no longer the spectical I remember.... or is it just me. I should add that the friend I was with whilst he did not understand the process did notice some of the things above. When did the change take place and does anyone else feel the standard has dropped.  |  IP: Logged Paul Trimboli Master Film Handler Posts: 274 From: Perth Western Australia Registered: Dec 2002 posted 04-21-2003 08:34 AM                     Well first let me say there is no reason why over and under 3D vrs dual system should be better then one another in the 3D effect. I know most things there is too know about 3D. Having shot my own 3D test films, I have read a book on the topic and more. Polarised 3D is better then shutter method becuase the shutter method has the crippling effect of not being able to present both images to the eyes at the same time. So on a quick pan a rippling effect can happen. I am not sure why cinemas are not considering showing the 3D with 2 pretty bright video projector and getting the film on dual HD DVDs? I have been looking it to it for the cinema I work at. Nwave can supply me their films on 2 HD 32mbps DVDs.  |  IP: Logged Andrew Lee Film Handler Posts: 99 From: Oakville, Ontario, Canada Registered: Jun 2002 posted 04-21-2003 08:56 AM                     Ken, I believe Imax has changed out or is in the process of changing out their electronic 3D glasses to passive in all their theatres. Although the shuttered liquid crystal glasses provided a superior presentation over polarized, the cost of maintaining the electronic glasses as well as logistics in handling made them less than desirable to theatre owners. The electronic glasses were somewhat bulkier to wear and most people seemed to prefer the lightweight aspect of the polarized type. I'm glad there are people out there who actually noticed the difference. Cheers! Paul, what colour is the sky in your world? Since when are "quick pans" a factor in filming of 3D presentations. The only reason theatres are showing GOTA in under/over is that it is the only way it can be presented within a reasonable budget. Dual 35 as well as 2 video projectors are not only costly, but most current projection rooms are not equipped for either.  |  IP: Logged Paul Trimboli Master Film Handler Posts: 274 From: Perth Western Australia Registered: Dec 2002 posted 04-21-2003 09:14 AM                     Last time I check it was blue! When I said quick pans, this referse to when shutter type glasses are used. This is a well know fact. Think about it, if each eye is not reciving both images at the same time is not as good as both of the images being seen at the same time. The rental of portable bright projectors are not expensive for shows. I don't mean fulled sized DLP projectors. Just general sized LCD or DLP portable projectors.  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 04-21-2003 01:56 PM                     Generalized LCD portable projectors are not even in the quality ballpark for comercial showings unless one is saying quality doesn't matter As for panning with the shutters that is not an issue as the original source is descreate source. Also I believe the flicker rate on the LCD glass/shutter is high enough it is not an issue  |  IP: Logged Mark J. Marshall Film God Posts: 3188 From: New Castle, DE, USA Registered: Aug 2002 posted 04-21-2003 03:39 PM                    I'm curious. Re IMAX Shutter 3D, is that a single strip film with alternating images? And if so, does it run at 2X speed?  |  IP: Logged Andrew Lee Film Handler Posts: 99 From: Oakville, Ontario, Canada Registered: Jun 2002 posted 04-21-2003 03:57 PM                     Gordon is correct....as usual. The flicker rate in an Imax LC 3D presentation is well above what the human brain can perceive. I beleive the flicker rate is actually 96Hz (24 fps x 2 flicker shutter x 2 eyes) if you look at it as a whole or 48Hz per eye. The Imax 3D system uses two films, not one film with an alternate frame.  |  IP: Logged Adam Martin I'm not even gonna point out the irony. Posts: 3686 From: Dallas, TX Registered: Nov 2000 posted 04-21-2003 05:41 PM                     Imax has nothing to do with exhibitors choosing to change to polarized-only 3D glasses. It is simply a choice on the exhibitor's part to not deal with the high maintenance that the E3D system requires. Many theaters which have the E3D system are simply using the polarized part of the electronic goggles and have the shutters disabled. Because of this, Imax has decided (from what I understand) to no longer install E3D systems. They do, however, continue to service them and continue to offer refurbished goggles to the exhibitors. Exhibitors are not required to purchase the nice XR polarized glasses from Imax. They may choose to use glasses manufactured by a third party. Unfortunately, these glasses are often less effective at extinguishing opposite-eye image ghost and are usually a lot flimsier. So please don't let one theater's cheapness ruin your opinion of Imax 3D in general. Additionally, keep in mind that for this particular film, the source material is from HD video, so there's no way it's going to look as good as what you're used to seeing in 15/70. The 3D does, however, hide a lot of the flaws. The dual-projector systems (SR or dual classic) are the only Imax systems that show both images flickering at the same time. The GT rotor has the right eye running a quarter frame behind the left eye (the first impression on the right eye occurs as the left eye flicker shutter passes the image). The strobing that you perceive is caused solely by the speed of the camera movement and is noticeable in many of the 2D films that I have run. At 24 fps with a frame that large, an object can only move so fast across the frame before it appears to be jumpy. It's not as noticeable with slower-speed films because the image blurs together (or with any system that is under-lamped). Rippling is a completely different matter. If you see rippling between the two images, then the images are seriously out of sync. I've noticed slight rippling with as little as one frame off-sync, and have had theaters run films as much as three frames off-sync without so much as a single complaint. It all depends on what's in the frame and how contrasty it is. GOTA is being presented in over/under in 35mm because Disney is paying for the initial installations with the stipulation that if the film does well and expands, the additional installations will be covered by the exhibitors. I don't see Disney upgrading a bunch of booths with dual projectors and synchronized motors and additional platter systems when a much more cost-effective method is available for their "experiment". We rent portable LCD projectors fairly often here. A 7700 lumen Sanyo projector rents for anywhere from $500-1000 per day depending on the deal we work out. Not exactly cost-effective for this situation.  |  IP: Logged Steve Kraus Film God Posts: 4094 From: Chicago, IL, USA Registered: May 2000 posted 04-21-2003 06:53 PM                    Adam, what is the purpose of having the two films 90° out of sync? If they were clever and had a spinning mirror so both films could share one lamp it would be cool(er, pun intended) but obviously that's not the case.  |  IP: Logged Ken McFall Jedi Master Film Handler Posts: 615 From: Haringey, London. Registered: Apr 2001 posted 04-22-2003 02:07 PM                     I'd worked out it was a cost consideration. I remember seeing those rows of headsets on charge and the cleaning and checking etc etc... It's a shame that the 'Standard' is not enforced so that IMAX is always best it can possibly be. Unfortunatly they don't drop the ticket price to reflect the saving from using cheap glasses. It's just another cinema experience.... popcorn & coke and adverts....... THX seem to be going the same way by introducing a new standard for the older movie palaces that can't reach the usual standards..... according to another post on here. I think all they will achive is to reduce the brand name 'value' in the long run. But hey.... it's cheaper to run and maintain so it must be good.  |  IP: Logged Claude S. Ayakawa Film God Posts: 2738 From: Waipahu, Hawaii, USA Registered: Aug 2002 posted 04-22-2003 02:41 PM                        The WAikiki IMAX Theatre here in Honolulu has been playing 3-D IMAX films ever since Consolidated installed the equipment after they bought the thetre from Destination Cinema about two years ago. The theatre has always been using IMAX issued Polaroid glasses and not the electronic type I used when I saw my very first 3-D IMAX film in New York City a couple of years ago and could not tell the difference between the two because they were both great. I also saw the T-2 show in 3-D at Universal Studio's theme park in Orlando shortly after it was released and I think they also used the regular Polaroid glasses and it too was awesome! -Claude  |  IP: Logged Paul Trimboli Master Film Handler Posts: 274 From: Perth Western Australia Registered: Dec 2002 posted 04-23-2003 08:06 AM                     I belive 2 video projectors with enough brightness and res would look very good on a fairly large screen, not something tooooo big. At work I have seen a video projetor used with a widescreen lens and the image looked very good. The projector that we play the adds from is only a cheaper model yet even from the front row the pixels are barly evident, have to look really hard. A company is selling software to use with these digital 3D servers and already a couple of cinemas are running it. http://www.lightspeeddesign.com/3d/3d.html  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 04-23-2003 08:26 AM                     Paul you will need over twice the light level per projector of non 3d just to overcome the losses on the two sets of polarizers (one on the lens and one in the glasses) A polarizer typically represents 2 fstops of light reduction And unless the screen is real small pixels are evident and it is definitly not a film done right solution  |  IP: Logged Adam Martin I'm not even gonna point out the irony. Posts: 3686 From: Dallas, TX Registered: Nov 2000 posted 04-23-2003 11:17 AM                     Many LCD video projectors somehow polarize one or more of the color panels. The Mitsubishi projector ($9,000 price range, producing a nice 30-foot wide image) I installed in the Grand Rapids Imax theater did this. If you were wearing the polarized 3D glasses while watching the video preshow, one eye could not see one color and the other eye could not see another color. This resulted in severe eye strain and I had to re-polarize the light with a spare Imax filter after it exited the main lens so that both eyes could see all the colors in the 2D image. I can't imagine what I would have had to do to produce a decent 3D image under those circumstances.  |  IP: Logged Fred Georges Master Film Handler Posts: 257 From: Lombard, IL, USA Registered: Jun 2000 posted 04-23-2003 11:02 PM                     Adam is so correct. All LCD projectors that I am aware of use internal polarizers which render them unusable for polarized 3D projection. They can be used with the shutter glasses system though. You need a DLP or ILP or conventional CRT system to do polarized video projection. I've done it in an industrial situation using 2 Sony Graphics grade CRT projectors on an 8ft silver screen with stunning results.  |  IP: Logged

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