Digital cinematography is the process of capturing motion pictures as digitalimages, rather than on film. Digital capture ...
Many vendors have brought products to market, including traditional filmcamera vendors like Arri and Panavision, as well a...
Other factors, such as improved speed, security and the ability to connect to thepostproduction already while shooting are...
latest digital technology. However, digital images are just a few decades oldand their stability is yet to be proved. Some...
time print of an 80-minute feature[8]), so making 4,000 prints for a wide-releasemovie might cost $5 million. In contrast,...
and also helps the Script Supervisor. It is very easy to check shooting       angles, correct overlaps, and time camera or...
Commonwealth Games held in Delhi as well as the cricket world cup werecovered on HD. The world has now moved on to the HD ...
a) Very good picture quality.                 b) There is no interference as the signal is directly received              ...
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Digital vs film & signals

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Digital vs film & signals

  1. 1. Digital cinematography is the process of capturing motion pictures as digitalimages, rather than on film. Digital capture may occur on tape, hard disks, flashmemory, or other media which can record digital data. As digital technology hasimproved, this practice has become increasingly common. Many mainstreamHollywood movies now are shot partly or fully digitally.This is a technique of shooting on film, scanning the film into digital format forvarious reasons, and ‘recording’ back to film for printing. So you begin and endon film with an intermediate stage that is digital. Initially, this technology wasreserved for when it was needed the most when the shot required extensivecomputer manipulation and other effects digitally. Eventually as the costsdropped and the process became more streamlined, more common opticaleffects could be done digitally instead.Finally, some filmmakers started using digital intermediate technology forchanging the colors in a shot, giving them access to the far more powerfulcolor-correction tools than available with simple 3-color printing. Withstandard printing, you could simply make a shot redder or bluer, for example.However, with digital color correction, you could change the contrast and blacklevels, you could do mid-shot corrections, you could manipulate the colors ofsome areas of the frame but not the others and so on. At first, only select scenesreceived the DI treatment, but after a while entire films were being colorcorrected this way.The basic steps in DI technology are as follows:Shoot on film to get the best image, which of course is processed in a lab.Scanning: The original film is scanned into a digital format.Color correction and other effects: All kinds of digital manipulations are donein this stage. It also includes dust removal, checked for scratches and any othercorrection that may be necessary.Recording: This is a reverse process of scanning where the digital informationis back on celluloid, usually to a 35mm internegative (or dupe negative).Release prints: Married prints are made from this dupe negative along with thesound negative for theatrical release.The first step of using celluloid film can be done away with, although withsome compromise in quality, by using high-end digital cameras. A minimumscanning resolution of 4000 pixels horizontally (the number of pixels verticallydepends on the aspect ratio) is considered necessary to capture all theinformation on a 35mm motion picture frame. This is referred to as ‘4k’resolution. However, a half-resolution scan of 2000 pixels across (‘2k’) isconsidered adequate for a number of practical purposes; 2K scans are faster andmore affordable, although that will change as technology keeps improving. Atthis time, the majority of DI work has been done on 2k resolution. While this issomewhat a compromise for the 35mm frame, it is completely adequate for16mm frame.
  2. 2. Many vendors have brought products to market, including traditional filmcamera vendors like Arri and Panavision, as well as new vendors like RED andSilicon Imaging, and companies which have traditionally focused on consumerand broadcast video equipment, like Sony and Panasonic.The benefits and drawbacks of digital vs. film acquisition are still debated, butdigital cinematography cameras sales have surpassed mechanical cameras in theclassic 35 mm format. Digital cinematographys acceptance was cementedwhen Slumdog Millionaire became the first movie shot mainly in digital to beawarded the Academy Award for Best Cinematography.[1]SensorsDigital cinematography cameras capture images using CMOS or CCD sensors,usually in one of two arrangements.High-end cameras designed specifically for the digital cinematography marketoften use a single sensor (much like digital photo cameras), with dimensionssimilar in size to a 35 mm film frame or even (as with the Vision 65) a 65 mmfilm frame. An image can be projected onto a single large sensor exactly thesame way it can be projected onto a film frame, so cameras with this design canbe made with PL, PV and similar mounts, in order to use the wide range ofexisting high-end cinematography lenses available. Their large sensors also letthese cameras achieve the same shallow depth of field as 35 or 65 mm motionpicture film cameras, which is important because many cinematographersconsider selective focus an essential visual tool.Some professional digital cinema cameras which have been designed to satisfyprofessional DoPs include: Sony CineAlta Thomson Viper Silicon Imaging SI-2K Panavision Genesis Arriflex D-20 Dalsa Origin Red One Panasonic VariCamFor more on this http://en.wikipedia.org/wiki/Digital_cinematography_camerasHollywoodOn higher budget productions, the direct cost advantages of digitalcinematography are not as significant in relation to the total budget, primarilybecause the costs imposed by working with film are not the only majorexpenses for such productions.
  3. 3. Other factors, such as improved speed, security and the ability to connect to thepostproduction already while shooting are also important factors which oftenplay a role when A-budgets are shot digitally and not mechanically. Skippingdeveloping the negative, linking live via satellite or data networks, on setbackups of the shots and immediate availability of high-quality dailies on blu-ray, hdcam or file-base have become commonplace for many directors andDirectors of Photography.Recent films, such as Sin City and Superman Returns, both shot on digital tape,had budgets of $40 million and close to $200 million respectively. The costsavings, probably in the range of several hundred thousand to over a milliondollars, are not negligible for todays producers.The mentioned security and speed advantages are an important reason to shootdigitally for many producers. The ability to check expensive shots at once onset, the possibility to backup and copy shots lossless directly at the set, theimmediate transfer to postproduction as well as remote viewing by directorsallow massive cost- and timesavings and reduce risks.Rick McCallum, a producer on Star Wars Episode II: Attack of the Clones, hascommented that the production spent $16,000 for 220 hours of digital tape,where a comparable amount of film would have cost $1.8 million. With disk-basing systems as the Red one or the SI 2K, the cost would be even lower, andexact backups can be stored at different locations on different media as well.However, this does not necessarily indicate the actual cost savings percentage,as the very low incremental cost of shooting additional footage may encouragefilmmakers to use far higher shooting ratios with digital. Lower shooting ratios,no matter if with mechanical or digital cameras, may save time in editing, ormay make the team miss interesting shots.Digital versus filmQuality: The quality of film is still considered as the ultimate though theadvancements in digital medium are rapidly progressing.Cost: The cost of film and processing is a disadvantage with film. Digitaltechnology scores over film on this aspect. Besides films are not reusable andalso you pay for processing all the NG shots also. In digital medium, it ispossible to delete the shots on the spot if it is felt that they are not usable at all.High quality film cameras are less complicated and therefore less expensive.The major expenses are ongoing film and processing costs. Digital cameras arecomparatively expensive.Performance: The flexibility that film offers to a DoP is not available on digitalcameras. For example, the contrast handling capabilities (highlights versusshadows) are wider in film than digital. Film is more ‘forgiving.’ Digitalscores over film as it is instant. One has to wait for film to be processed andprinted and then use a projector to view the visuals.Archiving: Feature films which are almost a century old are still in goodcondition even now. Some decline in quality can be corrected by using the
  4. 4. latest digital technology. However, digital images are just a few decades oldand their stability is yet to be proved. Some films shot on digital medium havebeen printed on to celluloid as backup for archival purposes.Digital is always stuck in whatever quality you shot it. Digital or video hasnothing to rescan. What you got it is all youre going to get. This is whyHollywood shoots movies, and even the better TV series, on film. 10 or 50years from now they can still get better and better images by rescanning them.Go watch the latest DVD of The Wizard of Oz shot on film in 1939. Theysimply went to the vault and rescanned the film with modern technology.PERMANENCE: Film does not erase itself. Film does not become unreadablefor no reason. It doesnt have file compatibility problems. Traditional black andwhite film and prints will outlast any of us.COST: Digital cameras are very, very expensive for what they do. Theybecome obsolete in a year, unlike film cameras in which even 50 year oldcameras and lenses are in use daily.Film: Film is still higher in resolution Cameras are generally heavier Film can take up a lot of space Film is a continuing cost Film must be developed before viewingDigital Higher initial cost Can easily lose detail in whites and blacks Cameras are generally lighter One memory card can store more images than a dozen rolls of film Images can be viewed immediately You can edit your images Only print the images you likeDigital cinema refers to the use of digital technology to distribute and projectmotion pictures. A movie can be distributed via hard drives, optical disks orsatellite and projected using a digital projector instead of a conventional filmprojector. Digital cinema is distinct from high-definition television and inparticular, is not dependent on using television or HDTV standards, aspectratios, or frame rates. Digital projectors capable of 2K resolution begandeploying in 2005, and since 2006, the pace has accelerated. (2K refers toimages with 2048 horizontal pixel resolution.)Savings in distributionDigital distribution of movies has the potential to save money for filmdistributors. A single film print can cost around US$1200 (or $30,000 for a 1-
  5. 5. time print of an 80-minute feature[8]), so making 4,000 prints for a wide-releasemovie might cost $5 million. In contrast, at the maximum 250 megabit-per-second data rate (as defined by DCI for digital cinema), a typical feature-lengthmovie could fit comfortably on an off the shelf 300 GB hard drive—which sellfor as little as $40 (retail price, volume prices are even lower) and can even bereturned to the distributor for reuse after a movies run. With several hundredmovies distributed every year, industry savings could potentially reach $1billion or more.Greater protection for contentA last incentive for copyright holders for digital distribution is the possibility ofgreater protection against piracy. With traditional film prints, distributorstypically stagger the films release in various markets, shipping the film printsaround the globe. In the subsequent markets, pirated copies of a film (i.e. a cam)may be available before the movie is released in that market. A simultaneousworldwide release would mitigate this problem to some degree. Simultaneousworldwide releases on film have been used on The Da Vinci Code, Lord of theRings: Return of the King, Star Wars: Revenge of the Sith, Charlies Angels:Full Throttle and Mission: Impossible III amongst others. With digitaldistribution, a simultaneous worldwide release would not cost significantlymore than a staggered release.For more info visit http://en.wikipedia.org/wiki/Digital_cinema1. What is video assist and how has it revolutionized film making? Video assist is a system used in filmmaking which allows filmmakers to view a video version of a take while it is being filmed. Originally a small device, called the video tap, was installed inside a movie camera that allows (with the addition of a monitor) the director to see approximately the same view as the camera operator, and thus ensure that the film is being shot and framed as desired. This is done by using a small chip (similar to ones in consumer camcorders) inside the viewfinder. The chip, together with its electronics, lens system and mounting hardware is the video tap, and was commonly called video assist until the video assist industry grown large. Camera gear like the jib was possible only with the invention of VAs. While a very simple video assist equipment is only capable of showing a live image, the modern VA equipment does much more than that. The image feed from cameras are recorded onto an inexpensive medium (usually MiniDV or Hi8) and nowadays on hard disks. The VA operator keeps a precise log about which take was recorded where, noting the time code or file name. He or she is then able to play back any shot in a short time, even right after the shot. This is essential for a director to show actors where to change their moves, or to recheck dialogue lines,
  6. 6. and also helps the Script Supervisor. It is very easy to check shooting angles, correct overlaps, and time camera or stunt actions. The VA recorder can usually simulate the under-cranking or over-cranking of the camera, and speed up or slow down the action. Ramps (speed changes in the shot) can be shown also. The Video Assist gear often includes a portable editing system (usually a laptop with a digitizing box and an editing software), so rough cuts can be made by the VA operator right on set. A portable video mixer is useful to check out key, blends or pre- visualize visual effects. A video printer is often used to print out pictures or hard copies of sets, camera angles or faces for art designers, make-up artists, and storyboard artists. Sound engineers and make-up usually requests a separate, live-only feed to know whats happening in front of the cameras and so dont need to continuously pop in and out of set. 2nd units or splinter units shooting extra shots or b-roll can take away small VA recorders to record their own footage, which is then loaded into the main unit archive so it can be watched and checked against main unit footage.Television: A television image is formed by scanning the optical image with anelectronic beam using a cathode ray tube (CRT). The number of horizontallines in NTSC is 525 and is projected at 30 frames/sec. PAL system has 25frames and 625 lines per frame. The image is reproduced in a reverse fashionwhere the electronic signals scan the phosphor-coated television screen and thescreen glows proportional to the strength of the signal thus reproducing theoriginal image. CRTs have now been replaced with CCDs (charge-coupleddevice). Television sets are available in both CRT and LCD forms now.Interlaced scanning: The lines scanned for video (625 or 525) is not done oneby one but done alternately. In other words the odd lines are scanned first andthen the even lines. This was done in the earlier days of television to overcomethe problem of flicker. It continues even now as CRT monitors can displayflicker-free images only with interlaced scanning. The system which usesinterlaced scanning is usually referred to as 525i or 625i.Progressive scanning. This is a method in which the lines are scanned one afterthe other i.e., 1,2,3,4,5, and so on. LCD monitors are capable of playing backprogressive images without any flicker. In progressive mode, it is usuallyreferred to as 525p or 625p.High-definition TV: By increasing the number of lines, it is possible to getsharper images and thus was born the high-def TV. High definition can be 720lines (referred to as 720i or 720p) or it can be 1080 i or p (sometimes referredto as full high definition) and is gradually replacing the older system of NTSCand PAL. Major events are now covered on high-def format and the recent
  7. 7. Commonwealth Games held in Delhi as well as the cricket world cup werecovered on HD. The world has now moved on to the HD platform.Distribution of TV signals: 1) The terrestrial method: This is the oldest and the first method of TV transmission. In this method, a transmitting antenna from the TV studio radiates the signals. The reach of the signals depends on the height of the transmitter and the strength of the signal. A typical 10 KW transmitter has a radius of about 120 kms. The receiver uses an antenna on the rooftop which is connected to the TV to receive the transmission. Only Doordarshan uses terrestrial transmission. The TV signals are not consistent and the picture quality varies. Further, the quality drops as the distance from the transmitter to the receiver increases. A major drawback in this method is that only one channel can be aired. This method can only be free-to-air. Only a limited area can be covered and a very expensive method of transmission. 2) Cable TV: In this method, the TV signals are beamed to a satellite and cable operators download the encoded signals. In turn, they distribute the signals to a limited area in their locality using coaxial cables. Advantages: a) Several channels can be beamed simultaneously. b) The cable operator collects subscription and thus it is possible to have pay channels. c) The quality is better than terrestrial transmission. Disadvantages: a) The quality of the signals are good only in the prime band and gradually the quality gets from bad to worse. b) Cables have to be run from the operator to each subscriber. Cables have to be maintained. c) A power outage at the operator results in total shutdown of all channels. Also, amplifiers have to be set up in order to boost the signal strength to subscribers who are far off. A new method of cable TV dissemination in the form of digital encoder/decoder has now solved the problem of the quality and now signals across all the channels are equally good. DTH: Direct to home: This is the latest technology through which signals are beamed to the satellite and each subscriber is provided with a small dish which is mounted on the rooftop. The quality of the signal is extremely good across all channels. It is also possible to air HD TV using DTH technology. Advantages:
  8. 8. a) Very good picture quality. b) There is no interference as the signal is directly received from the satellite. c) Revenue is generated from each subscriber as he has to pay every month. d) The subscriber has a choice to choose and pay for only those channels that he wants. e) Possible to have some interactive channels too.Disadvantages:a) Under vey cloudy conditions, there is no signal and hence all channels areblocked.b) All channels are not available on any of the DTH platforms as somepackages are found in one operator but not in another.

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