3D Cinema

3D Cinema is undoubtedly back with us, being touted as the saviour of cinema, once again. Is it another tool in films ever expanding toolbox, or should it only be used when the effect can truly be felt. Whether it is here to stay, or is yet another passing fad still remains to be seen but with the monumental success of James Cameron's Avatar, then maybe we are finally seeing a coming of age for this technology?

Of course everyone is screaming 'new' - it may be different but actually how new is it? In fact when you look at the history of 3D or stereoscope, it is as old as film itself. The stereoscopic era of motion pictures began as far back as the late 1890s when British film pioneer William Friese Greene filed a patent for a 3D movie process. In his patent, two films were projected side by side on screen. The viewer looked through a stereoscope to converge the two images, because of the obtrusive mechanics behind this method, theatrical use was not practical but it did set precedence. (Friese Green is mainly celebrated for his pioneering work in creating colour in film.)

Many different formats and ideas have been tried and tested for 3D over the years. The early 50s was a time where it was championed extravagantly, alongside many other new and elaborate projection formats such as Cinerama, which needed no less than three projectors in synch to project a single film.

The point is, early pioneering ideas were difficult to manage, not least because of the expense. For original 3D screenings, you needed two prints, two projectors and possibly two projectionists running them, or it could be disastrous. The drawbacks were many:

  • Two prints had to be projected simultaneously
  • The prints had to remain exactly alike even after repair, or synchronization would be lost
  • It sometimes required two projectionists to keep sync working properly
  • When either prints or shutters became out of sync, the picture became virtually unwatchable and accounted for headaches and eyestrain, which many patrons complained of
  • The necessary silver screen was very directional and caused sideline seating to be unusable with both 3D and regular films, due to the angular darkening of these screens


Short lived Revival - 80s

The early 80s also saw a revival, although bizarrely it seemed to be very much a horror led ambush. I remember seeing Jaws 3-D with a pair of disposable polarized cardboard red and blue anaglyph glasses at the local cinema. From memory it was rather an uneventful film, even the climax was a little disappointing.

Jaws utilised new technology, it was shot using the Arrivision 3D system. This used filmed 3D movies in normal colour, with a single camera and single strip of film - the Arrivision 3D technique uses a special twin lens adapter fitted to the film camera, and divides the 35 mm film frame in half along the middle. Capturing the left eye image in the upper half of the frame and the right eye image in the lower half - this is known as over/under (2Perf). This allows filming to proceed as for any standard 2D movie, without the considerable additional expense of having to double up on cameras and film stock for every shot. It was assumed back then this would pioneer the way forward for 3D cinema.

When the resultant film is projected through a normal projector (albeit one requiring a special lens that combines the upper and lower images), a true polarised 3D image is produced. This system allowed 3D films to be shown in almost any cinema since it does not require two projectors running simultaneously throughout the presentation - something most cinemas are not equipped to handle. It will also always remain in synch, if there was a problem.

The only requirement of the theatre is both the special projection lens and a reflective silver screen. This enabled the polarized images to reflect back to the viewer, with an appropriate filter on each eye blocking out the wrong image, thus leaving the viewer to see the movie from two angles as our eyes naturally see the world.


Could a severed arm save 3D? Not in the 80s.


As technology has progressed I suppose it was inevitable 3D made a resurgence. Digital projectors are not hindered by mechanics, moving parts, a limitation on frame speed or something as fragile as the film itself, so they certainly lend themselves to 3D or stereoscope. Also a 3D digital presentation does not require two projectors, unlike some older 3D stereoscopic projection technology. It can be projected with a single Christie, Barco or NEC DLP cinema projector (other digital projectors will work if fitted with the proper equipment). Today, there are three leading companies offering systems to project 3D - RealD, Xpand/NuVision and Dolby.

How Does It Work?

Audiences viewing a film presented in 3D are given a pair of plastic glasses. Unfortunately we still can't escape the glasses. The glasses have circular polarized lenses, each polarized differently. Circular polarization allows much greater head movement than linear polarization without loss of 3D effect or ghost images. This increases audience comfort and helps to subdue the 3D headache complained about in previous incarnations.

The movie is projected digitally, with a single DLP projector at 144 frames per second, six times faster than a normal movie. Every 1/24 of a second (the frame rate for normal film) the two scene views referred to as the right eye and left eye are each shown 3 times (6 flashes of image on the screen matching the 6 times higher projection rate). Due to persistence of vision, the 72 image frames and 72 black frames fed to each eye in a given second should be perceived as a relatively flicker-free image.

The systems all offer a variation on a theme but the principal is the same, both projecting the right and left eye - however the technology employed during projection and re-combining of the right and left eye images require the viewer to wear specialized glasses. Independently viewing the two different images from the right and left eye, you will see the same view but slightly shifted version of the frame. During projection the brain knits together the alternating left-right perspectives into a seamless 3D view of the movie scene.

The single projector setup has a number of advantages over previous 3D systems:

  • It eliminates most "ghost images" caused by the left eye seeing a bit of the right-eye frames and vice versa.
  • It eliminates any form of temporal (time) or spatial misalignment of the left eye and right eye frames which plagued previous 3D projection systems relying on movie (print) film. The mechanical jitter of the film in the projector is removed and the poor frame-to-frame synchronization eliminates most of the dull headache or side effect caused by eye muscle strain.

The biggest problem with polarized 3D systems for movies is a loss of screen brightness. As every other frame is 'invisible' to one of your eyes, the image would seem only half as bright, if projected onto a normal screen. However, this loss of brightness is counteracted to some extent by the fact that theatres use a silver screen for this type of projection. A normal white matte screen dissipates the polarization of the projected light. The separation of the two images is lost without the silver screen.



Interestingly although I do think this is a great opportunity for the industry to reinvent itself. The cost to an individual cinema is rather out weighing the benefits presently! Every cinema has to invest to replace the screen and projector within each auditorium, which is just not cheap at all. Even the digital projectors they have already invested in need upgrading constantly with software updates and patches at an additional cost to the cinema itself. It will ultimately be reflected in the cost of admission - independents run on a shoe string presently, so how does this help them?

Many cinemaphiles are a little perplexed at the cost of the admission ticket but what the cinema going public do not seem to acknowledge is the percentage the distributors skim off the top. For instance in the opening week, upwards of 60% may be taken, even as much as 90%! Leaving the remainder for the establishment to pay massive council rates (with such big buildings), water, electric, gas, staff and other sundries, it is certainly not a cheap business to be in - Marilyn, the manageress of a small independent cinema who I support avidly, often quotes "we are a sweet shop that happens to present film!"

The Royalty Cinema's Circle, Bowness on Windermere - Independent Cinema, Charles Morris Proprietor

Many of our 600 or so independents that are trying to survive in the UK will find the cost simply too expensive to update and install the required equipment. The initial costs for converting standard 35mm theatres to digital are high: up to £80,000 per screen or more. While a theatre could purchase a film projector for £25,000 and expect a lifetime of 30–40 years, a digital system including server and projector can cost 3–4 times as much, and is at higher risk for component failures and technological obsolescence. You will see many of the independents closing their doors for the very last time if the trend continues - which personally I believe is a real shame.

The point is, if the distributors greed force too much of the takings into their own coffers without little concession to the theatre itself, they will have very few cinemas to exhibit in - I fear this is simply biting the hand that feeds them. Ultimately our cinemas will become bland, generic, uninspired and look more akin to a factory than a place of entertainment.

Are you seeing the emerging trend?


The Future

There are many films being green lit for release using 3D. I assume Avatar proved how profitable they can be and now that many cinemas have invested in the technology it is only the initial finance which prohibits a 3D production. The biggest problem I see is that we are now faced with is the age old concern of content. Is it worth the extra cost, when a purely story driven narrative may not benefit at all from 3D. Or an already overbloated, expensive FX driven film will cost more to produce and ultimately push budgets using 3D?

3D does cost more to post produce, so it certainly is and will be a factor for budgets on smaller productions. The dilemma will always continue as technology evolves. Investment has been huge for either party. It now remains for the film industry to deliver, or it will indeed end up being a rather indulgent and expensive fad like it so often has in the past? The answer lies in streamlining productions and ultimately making presentation cheaper; this will push both sides of the industry drawing the cinema audience back.

Using 3D, just because, does not make a seat worth the considerably over inflated ticket price. Especially when it could easily have been made in 2D or only when the narrative has call for it. It is indeed a great tool for story telling and great visuals, an extra tool used by the director and in my humble opinion it should be used sparingly and only when it enhances a film. It should also not be used in a few scenes throughout a film so they can charge the extra 3D premium, which is something I have seen of recent - personally I feel that kind of profiteering is scandalous.