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Author Topic: Real D & Dolby 3-D - What is the difference? Julio Roberto Jedi Master Film Handler Posts: 938 From: Madrid, Madrid, Spain Registered: Oct 2008 posted 12-21-2008 09:33 AM                    quote: Mark J. Marshall Also, what is that over/under frame from? Hmmmm ... you got me. By the looks of it it's either that new Chotta Chetan movie remake, Jadugar or perhaps Domo Arigato. Most over/under systems would, indeed, show part of a frame slightly earlier or later than the other on "fan-blade" type shutters as it sweeps from top to bottom while the eyes still had persistence of vision from the prior frame in the other eye. This would've theoretically put one "field" (one eye) on the screen while the other was still black and viceversa. And it would've been at 24fps x 2 blades x 2 "fields per frame" x 2 scan on/off cycles, so at the equivalent of 192hz in digital (where there is no need for a "black" interval to allow for the frame to advance). Nobody ever complained about it or, as far as I know, it has never even been brought up anywhere. I guess it's like film's rolling shutter: nobody thinks that it's a problem that the negative gets exposed (say) from the top first and then lower-and-lower until the whole frame is exposed while the subject is moving. It happens fast enough that it's considered like if the whole frame was exposed at the same time. With single projector Digital 3D a "frame" for one eye is shown for aprox 1/134th of a second (the other eye won't see it and get no light), then 1/010th of a second of black is commanded to the micromirrors (so the Dolby filters or RealD zscreen have time to reach the correct position, during this time the light is lost and both eyes see black, like a shutter) and then the other "frame" is shown for the other eye. This is repeated 3 times showing the same frames and then we proceed to a new set of left-and-right-eye frames. Single projection digital 3D loses this aprox. 7% more of additional light for the blanking interval between "frames" that are played back at 144fps. Just for clarification, when a "frame" is divided into two images, one for each eye, like in the over/under film system, I like to refer to them individually as "fields" altough, of course, that only properly applies to interlaced systems (i.e. TV). Perhaps I should call them half-frames, but for me, to call each one of a pair of left-and-right "frames" fields is more confortable. [ 12-21-2008, 03:22 PM: Message edited by: Julio Roberto ]  |  IP: Logged Claude S. Ayakawa Film God Posts: 2738 From: Waipahu, Hawaii, USA Registered: Aug 2002 posted 12-23-2008 06:43 PM                        I still have not seen BOLT in Dolby 3-D but I hope to do so by this weekend. There is a $2.50 charge for the glasses at Dole Cannery for their Real D presentation on top of their regular admission. Is there an extra charge to see a Dolby 3-D presentation when we will be provided with a set of glasses we have to return after the show? As a senior citizen, I can see a regular show for $6.75. If there is an extra charge, how moch more will I be charged? -Claude  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 12-23-2008 09:28 PM                     The surchage is for the 3D presentation and it varies by theatre. I would certainly expect a similar surcharge...while you don't get to keep the glasses (and what would you do with the Real-D ones anyway?)...it still costs more to present in 3D and the theatre does have to keep up the glasses, and that costs money. 3D is a preminum, people are going to want to make money off of it. Steve  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 12-24-2008 04:54 AM                     quote: Julio Roberto I remember projecting a risqué american one that was side/side anamorphic (Stewardesses) I also ran "the Stewardesses" in 1972 as a relief operator since this one theatre had teenagers doing booth and were underage for to run an "X" rated film. (side note: "the Stewardesses is being released on DVD come the middle of next month..) But, this side-by-side anamorphic process was interesting in itself: Using Dichromic mirrors in our Peerlesses, the prime lens was split in the middle per each image with a common attachment to expand the image to a 1.33:1 image on the screen-which the side masking tabs had to be adjusted in to present such an image size, and using polarized glasses with our silver screen. -monte  |  IP: Logged Julio Roberto Jedi Master Film Handler Posts: 938 From: Madrid, Madrid, Spain Registered: Oct 2008 posted 12-24-2008 09:07 AM                    IIRC I projected that one with an integrated Scope lens and a Polarator prismatic adapter turned 90º from its normal position for over/under. I don't recall needing masking for that one, but when we did, we used soft masking taping cardboard on the projection booth window. Fun 3D 80's, indeed I hope Jeff releases the Stewardesses on blu-ray field-sequential or side-by-side. That would be a first  |  IP: Logged Richard Fowler Film God Posts: 2392 From: Ft. Lauderdale, FL, USA Registered: Jun 2001 posted 12-24-2008 12:12 PM                     There are established panning or tilting speed limit charts based on camera shutters moving across or up/down (depending on camera) during exposure. Double or barrel shutter on some projectors would exhibit different results, which our "slow" eyes and brain easily ignore.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 12-24-2008 12:55 PM                     Richard, Do those same rules apply to shooting 3-D digitally???  |  IP: Logged Richard Fowler Film God Posts: 2392 From: Ft. Lauderdale, FL, USA Registered: Jun 2001 posted 12-24-2008 04:45 PM                     Depends on the imager and processing. Seen lately on 2D Digital stuff rubbery motion artifacts on pans....On the Red some annoying "grain" that is not ramdom but progressively buzzing from one point to another. A recent HD transfer from 3 perf anamorphic ratio...still very familiar and filmic.  |  IP: Logged Julio Roberto Jedi Master Film Handler Posts: 938 From: Madrid, Madrid, Spain Registered: Oct 2008 posted 12-25-2008 05:00 AM                    quote: Richard Fowler Double or barrel shutter on some projectors would exhibit different results, which our "slow" eyes and brain easily ignore. Yeap. That's why I explicitely said "fan-blade type shutters" Limiting the pan speed etc during filming helps cover up the problem, but still doesn't solve it when an object is moving in the frame fast enough to become noticeable. Motion blur takes cares of covering most of the "faulty" (skewed) images. In digital, it depends on the camera technology used. With 3-CCD based techonology, there is no rolling shutter effect whatsoever, as they can be thought of as having a Global Shutter. With CMOS based imaginering, there is. How much, depends on the read-reset times. It can be made quite fast, and therefore only a fraction of what mechanical movie cameras are capable of achieving (i.e. much less noticeable in digital is possible and appearing in new CMOS cameras, but many cameras exists where the effect is more pronounced).  |  IP: Logged Ryan Navaroli Film Handler Posts: 63 From: Athens, OH, USA Registered: Nov 2005 posted 01-14-2009 05:28 PM                        We are set to install 3 Reel D houses by the end of February. I am not sure how locked this in this is as decisions were all rushed by upper management. After reading through some of the above on this post I had a few questions. 1) How do the Real D silver screens look when presenting a 2D digital print? 2) Someone said they wanted to see a cost of $6 for Dolby glasses. What are they currently priced at? Anyone operating Dolby have a rough estimate of number of lost glasses? 3) Are all the same 3D movies available from both set ups? 4) Any idea which has greater market share at present time (I'm guessing Real D with less initial cost)? Predictions on future market share or if one will win out format war and make obsolete the competitor? 5) I believe we are installing Christie 2000CP ZXs or something like that. Any thoughts on these? Are they compatible with both systesms?  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 01-14-2009 07:04 PM                     1) How do the Real D silver screens look when presenting a 2D digital print? > You'll have higher contrast but VERY directional light. In theory color shouldn't look any different because you can pull the color space as needed with the projector but I've always felt something looks funny about color on a silver screen. They also have extremely short lives. 2) Someone said they wanted to see a cost of $6 for Dolby glasses. What are they currently priced at? Anyone operating Dolby have a rough estimate of number of lost glasses? > Some claim they get the Real-D glasses for free but the location DOES PAY for them one way or another. Real-D does theor best to hide the actual cost. Dolby's...Well under 30.00 per pair right now. Unfortunately your higher ups don't know how to do math because the "Per Use" cost of the Dolby Glasses is about 10 cents per use including handling, washing, etc, etc. Remember, Dolby rates them for 450 cycles!! 3) Are all the same 3D movies available from both set ups? >Yes, so far but the advantage of Dolby 3-D is the print DOES NOT need to be Ghost Busted although a Ghost Busted print also plays fine on Dolby where as a non-Ghost Busted print won't play fine on Real-D. 4) Any idea which has greater market share at present time (I'm guessing Real D with less initial cost)? Predictions on future market share or if one will win out format war and make obsolete the competitor? >Real-D but that is slowly changing and I believe over the next two years the market will even out. There are MORE advantages to using the Dolby 3-D system. 5) I believe we are installing Christie CP-2000 ZXs or something like that. Any thoughts on these? Are they compatible with both systesms? >Yes, The ZX is compatable with any existing "Digital" 3-D system built so far. Its also one of the most reliable projectors you can buy and one of the most light efficient in existance even though it uses the 1.2" DMD chips.  |  IP: Logged Ryan Navaroli Film Handler Posts: 63 From: Athens, OH, USA Registered: Nov 2005 posted 01-14-2009 10:20 PM                        What exactly is ghost busted? Just ghosting correction? Is ghost busted something performed by the distributor or by the theater.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 01-14-2009 10:26 PM                     quote: Ryan Navaroli Just ghosting correction? Exactly. I'm not sure if the Distributer does it or if Real-D does the processing... But probably one or the other. There is no ghost issue with Dolby. Mark  |  IP: Logged Ryan Navaroli Film Handler Posts: 63 From: Athens, OH, USA Registered: Nov 2005 posted 01-14-2009 10:37 PM                        Thanks for your help. 3D at our theater kind of came out of the blue. We had talked about it for a while but it wasn't financially feasible until one magic day when my boss told me we got the money to do 3D. He's not the most research oriented individual and pretty much went off the advice of our equipment supplier. After weighing the facts I really hope I can convince him to go Dolby and that it isn't to late contractually. It really seems like If you add a similar surcharge to the 3d presentations that a Real D theater would add you will pay for the equipment after not so long and then profit more. I guess I thought of one more operations question too. With Real D they tax you a certain amount for the leasing of equipment and glasses. So you add $2 or so into your ticket price to cover this. $1 - Real D the other $1 split on terms I presume. Is it possible with either, more likely with Dolby I presume, but to charge your standard admission price and then tender a separate item for glasses rental? I.E. $7 Adult Ticket $1.50 Glasses Rental $80.00 Awesome Combo  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 01-14-2009 11:58 PM                     ..and it's funny on hearing of Real D installs - silver screens, locked in leases..et.al. .. and all I can think of is how the imagery would look if they went Dolby 3D: Yet more questions: Running Real D, esp on a silver screen, do you need a higher wattage of bulb, AND if shooting 35mm on that same silver screen, would there be any change in fL due to this screen change compared to a high 1.2 + gain matte white screen? thx-Monte  |  IP: Logged

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