Q&A

[Verbal_Kint]

Ovako, zamislio sam da ovo bude tema za opšta pitanja o filmu, za koja nigde drugde ne možemo naći odgovor. Dakle, ne za konkretne filmove, njihove naslove, glumce i režisere... Za to postoji ona "gledo, al' ne znam šta"... Više za pitanja filmske tehnike, objašnjenja opštih principa i tako to... Tipa: "koja je razlika između tog i tog tehničkog postupka u tom i tom aspektu"... Ako to ne možete da nađete na guglu, ili ne znate kako uopšte da formulišete upit za pretraživač, postavite pitanje ovde, pa će se naći neko da na njega odgovori, valjda... Imamo ovde i dva studenta FDU, pa će to, nadam se, nekako funkcionisati...

Predlažem da ova tema bude lepljiva.

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Pošto ne pokrećem novu temu bez zadnje namere, evo i razloga zašto sam je pokrenuo.

Sad ću da zvučim ko deca iz onih emisija kad ih pitaju "šta je oblakoder", al' šta da radim... Što kaže ĐB "Znam 100.000 reči, al' fali mi ona jedna da opišem" to što hoću...


Šta je uzrok onog "elektronskog, digitalnog šmeka" kod novih filmova? Ono kad gledaš, a kao da gledaš kroz filter:
plavi, žuti, crveni... Kao da između tebe i slike ima još jedan sloj neke fluidne materije, koja zamućuje ivice.
Strašno mi to smeta kod novih filmova, a ne znam da objasnim šta je, a kamoli da nađem pravi termin za to. Kao da
slika nema strukturu, nema sastavne delove, nema oštrinu... već se svi objekti prelivaju jedan u drugi na prilično
proizvoljnim mestima... kao da između njih nema jasne granice... kao bioskopski snimak, e to bi možda bio najbolji opis.

Oprostite ako mi reči deluju konfuzno, to je zato što su mi i misli takve.

Evo, recimo razlika između "strukture slike", ako tako nešto uopšte postoji, između ova dva filma:

Možda i umišljam, ko će ga znati...

 

[good_neighbour]

Ma gde umisljas...ja ludim od toga.

Nisam strucan da dam neko objasnjenje, ali mislim
da je stvar bas u kojekakvim filterima kao sto si rekao.

Cemu sve to? To mene zanima. Sve cesce, filmadzije
kao da se obracaju populaciji video igraca, a ne filmofilima.

 

[Verbal_Kint]

E, hvalim te Bože(!), taman sam počeo misliti da gubim dodir sa stvarnošću. Nekolicini ljudi sa kojima sam gledao poneki film pričao sam isto, ali svi su me bledo gedali, kao da nikakve razlike nema... Još na kraju ja ispadnem nenormalan.

Najgore što ne znam kako da ovom fenomenu uđem u trag preko gugla, jer ne raspolažem terminologijom. Nadam se da će se naći neko kompetentan da nam to ovde pojasni. Mislim da bi barem upola manje iritantno bilo, kad bih znao kako se to zove.

 

[V]

Resolution

Substantive debate over the subject of film resolution vs. digital image resolution is clouded by the fact that it is difficult to meaningfully and objectively determine the resolution of either. However the huge majority of all blockbuster-movie of the first decade of the 21st century have been finished in 2K - which can easily be surpassed by mechanical as well as digital camera systems.

Unlike a digital sensor, a film frame does not have a regular grid of discrete pixels. Rather, it has an irregular pattern of differently sized grains. As a film frame is scanned at higher and higher resolutions, image detail is increasingly masked by grain, but it is difficult to determine at what point there is no more useful detail to extract. Moreover, different film stocks have widely varying ability to resolve detail.

Determining resolution in digital acquisition seems straightforward, but is significantly complicated by the way digital camera sensors work in the real world. This is particularly true in the case of high-end digital cinematography cameras that use a single large bayer pattern CMOS sensor. A bayer pattern sensor does not sample full RGB data at every point; each pixel is biased toward red, green or blue [4], and a full color image is assembled from this checkerboard of color by processing the image through a demosaicing algorithm. Generally with a bayer pattern sensor, actual resolution will fall somewhere between the "native" value and half this figure, with different demosaicing algorithms producing different results. Additionally, most digital cameras (both bayer and three-chip designs) employ optical low-pass filters to avoid aliasing. Such filters reduce resolution.

In general, it is widely accepted that an original film camera negative exceeds the resolution of HDTV formats and the 2K digital cinema format, but there is still significant debate about whether 4K digital acquisition can match the results achieved by scanning 35 mm film at 4K, as well as whether 4K scanning actually extracts all the useful detail from 35 mm film in the first place. However, from 2000 to 2009, the overwhelming majority of films that used a digital intermediate were mastered at 2K, independent of their budget. Additionally, 2K projection is chosen for most permanent digital cinema installations, often even when 4K projection is available.

One important thing to note is that the process of optical duplication, used to produce theatrical release prints for movies that originate both on film and digitally, causes significant loss of resolution. If a 35 mm negative does capture more detail than 4K digital acquisition, ironically this may only be visible when a 35 mm movie is scanned and projected on a 4K digital projector. The most limiting factor when not using digital cinema however is the end of the exhibition chain: For mechanical projection, the SMPTE allows flutter and weave up to 0.2%, which reduces projected resolution down to 1K. Well maintained mechanical projectors however can operate at 0.05%, which can almost reach 2K resolution.
[edit] Grain & noise

Film has a characteristic grain structure. Different film stocks have different grain, and cinematographers may use this for artistic effect.

Digitally acquired footage lacks this grain structure. Electronic noise is sometimes visible in digitally acquired footage, particularly in dark areas of an image or when footage was shot in low lighting conditions and gain was used.

Since most theatrical exhibition still occurs via film prints, the clean look of digital acquisition is often lost before moviegoers get to see it, because most major releases are in the 35mm film format and all film stocks have film grain.
[edit] Digital Intermediate Workflow

The process of using digital intermediate workflow, where movies are color graded digitally instead of via traditional photochemical finishing techniques, has become common, largely because of the greater artistic control it provides to filmmakers. In 2007, all of the 10 most successful movies released used the digital intermediate process.[citation needed]

In order to utilize digital intermediate workflow with film, the camera negative must first be processed and then scanned to a digital format. High quality film scanning is expensive (up to $4 a frame, although the costs of this are continually dropping). With digital acquisition, the scanning step is not necessary. Footage can go directly into a digital intermediate pipeline as digital data, although with some digital acquisition systems, it may need to be processed into suitable formats before it can be worked with.

Some filmmakers have years of experience achieving their artistic vision using the techniques available in a traditional photochemical workflow, and prefer that finishing/editing process. While it would be theoretically possible to use such a process with digital acquisition by creating a film negative on a film recorder, in general digital acquisition is not a suitable choice if a traditional finishing process is desired. However, traditional photochemical finishes have become extremely rare for Hollywood features.

Digital capture

As of 2009, the most common acquisition medium for digitally projected features is 35 mm film scanned and processed at 2K (2048×1080) or 4K (4096×2160) resolution via digital intermediate[citation needed]. Most digital features to date have been shot at 1920x1080 HD resolution using cameras such as the Sony CineAlta, Panavision Genesis or Thomson Viper. New cameras such as the Arri Alexa can capture 2K resolution images, and the Red Digital Cinema Camera Company's Red One can record 4K. The marketshare of 2K projection in digital cinemas is over 98%. Currently in development are other cameras capable of recording 4K RAW, such as Dalsa Corporation's Origin and Canon's 4K "Multipurpose", and cameras capable of recording 5K, such as the RED EPIC, and cameras capable of recording 3K (for budget filmmakers) such as the RED SCARLET.

Jasno, a?

Zezanje na stranu, istina je tamo negde..

 

[Verbal_Kint]

"Additionally, most digital cameras (both bayer and three-chip designs) employ optical low-pass filters to avoid aliasing."

Hm, da, baš taj osećaj - kao da slika ne sadrži visoke frekvencije. Ali mi nije jasno kako ovog efekta nema pri transferu u digitalni format sa nekog tradicionalnog medijuma, jer, da bi bila moguća rekonstrukcija slike i ovaj signal je potrebno ograničiti u spektru, da bi se izbegao aliasing efekat. I tu je potreban nekakav low-pass filtar, kao i kod digitalne kamere. Jedino što mi pada na pamet je, da iz nekog tehničkog razloga, se digitalizovanje iz analognog medijuma može obaviti većom frekvencijom, sa filtrom koji ima veću graničnu učestanost, nego kod direktnog snimanja digitalnom kamerom, pa otud manje zamućivanja i odsecanja visokih učestanosti.

"Film has a characteristic grain structure. Different film stocks have different grain, and cinematographers may use this for artistic effect. Digitally acquired footage lacks this grain structure."

I ovo - zato imam osećaj da su digitalni filmovi fluidni, kako sam gore rekao, nemaju zrnastu strukturu.

"The process of using digital intermediate workflow, where movies are color graded digitally instead of via traditional photochemical finishing techniques, has become common..."

To bi valjda objasnilo problem sa bojom, koji uočavamo?


Dakle: bolje tradicionalno snimanje, pa transfer u digitalni format, nego direktno digitalno snimanje? Ili sam pogrešno razumeo?