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3D Filming principles

3D filming principles

JIJO Punnoose (director of S3D movies My Dear Kuttichattan & Chota Chetan)

Consultancy Budget is given at the end

3D (stereoscopic) Imaging originated much before photography itself. Full color dual stream (polorised glasses) is the best known 3D experience till date. This has its origin in 1940s by people like Poloroid's Dr. Land who invented industrial polorisers. Two Gurus of this medium's susequent development in filmmaking are

(1) The optical scientist Chris Condon (Century Optics/Stereovision/ Isco, under whom Navodayaʼs personnel including myself had our training), and (2) Academician Lenny Lipton (author Foundations of Stereoscopic Cinema) who now

heads the RealD supplying 3D projection solutions for new generation digital cinema. It was Condonʼs collaborator

Stereographer Mr. John Rupkalvis who devised the reticle used in 3D camera viewfinders. It helps calculate the parallax between the right/left images and allows the setting of convergence (a parameter that needs to be followed as lens focus, if eyestrain is to be avoided)

Shooting 3D Digital. This is cutting edge technology. We started our design & developments on this in 2003 with improvised 3D Beamsplitter rigs. We are still advancing on it with the arrival of newer and newer digital formats. Please refer website . This requires two cameras mounted on a rig. (We have a couple of custom-built studio rigs made by the ride fabricators of our amusement park. Also, there are special purpose 3D rigs available in California & Munich). Your advantage in this as against the single filmstrip format we used for My Dear Kuttichathan (1984) is the possibility to use any of the film lens (in matched pairs) of different focal lengths.

Another advantage is the variable interocular which gives better control on 3D (such as the possibility of extreme closeups and the use miniatures - which are not possible with a single lens 3D camera). Another major advantage is that you can see the projected image in 3D even as you shoot. This is possible on location with 3D-Ready TV & shutterglasses. For actual theatre simulation, this requires the setting up of a mobile dark cabin on a trailor which also house your media storage devices. With such a visual references the stereographer would be able to convince the director and the cinematographer about his calculations of positioning things in 3D space for every shot. Your disadvantages of shooting dualstream 3D Digital is that a rig has to be used for mounting the two cameras. This means, many of the available support systems cannot be used in shooting. This can be a very major concern for some filmmakers who are used to improvising shots on the sets.

For example, you just cannot decide at the shooting spot to put your camera on the side of a car. If such a shot is called for, it should be planned for in the storyboard session, and a rig support and mounting system should be improvised for a camera car.

(Above stills taken fom Chota Chetan and HD Demo done by MRT for prospective 3D using both live action and CG)

There has to be a Stereographer for a film project. Infact, the stereographers whom we have trained are acclaimed cinematographers themselves. One of them has to be contracted well in advance so he keeps his cinematography assignments free. During the shoot, a stereographer collaborates with the cinematographer as regards to lighting of the objects enhance 3D, the aperture value and plane of focus which is

critical for bringing objects out of the screen. Like the Stereographer our 3D Graphics consultant collaborates with the C.G. personnel of the given project for special effects and postproduction. It is their responsibility to see that all images are

converged well - if not, it shall give eye strain to the audience.

The consultancy fees for the project. 3D requires pre-planning. It requires guidance through scripting, production design, art direction, C.G., release printwork/encoding and upto theatre 3D alignment. The agency who provide you with the expertise should advise (through their own personnel in these areas), the people

you engage in the above areas for your film.

Now, the real cost of your 3D film is not in your 3D equipments or consultancy costs. From experience we have found that even with the best of planning, it takes 21/2 to 3 times the execution time for 3D, than it takes for a normal shoot. This can be explained only in an elaborate sitting. Also, to maintain a maximum depth of field it is mandatory to shoot at a minimum 5.6 lens T stop (after giving due allowance for the 50% division of illumination between the two images on the beamsplitter). If this is indoors, this is a very high key. Outdoors and shooting digital, then this is a lot of fill. In economic terms it means than everyday the lighting budget is about twice that of an equivalent shoot in a 2D production. Down the years people have tried to circumvent this cost by trying out production alternatives. But with limited success.

When you takeup a special format for your presentation, you have to have ingredients for justifying the selection of the format. For example, a large format (like Imax) works only when it has nature's wide open vistas.

For 3D to work, it needs (1) subjects moving between the auditorium space and screen space, (2) tightly composed subjects well moulded in x,y,z axes fascinating to watch. True, one can always find instances in a script that brings forth 3D possibilities But I am afraid that alone would not be sufficient. One has to incorporate narrative elements that would work for sure in 3D.

I am giving here some examples. ….. Flying/ gliding objects work well in 3D. Kites, flags …etc. If there are ribbons flying out in song sequences … well, a director can work ahead from that. There was once an Nokia ad (by JS) which had streams of digital numeric flowing in gentle waves from one subscriber to another. Such flowing subjects shall work well in 3D. Below, I have used music score notations emanating from musical pillars. Could even be swarms of bees or butterfies from flowers or beehives.

Exploding objects (captured high speed) work well in 3D. Water sprays, soap bubbles, shattering objects, fireballs. flamejugglery … etc. can be used as part of people’s activities.

Also in today's visualisation, C.G. and live shots cannot to be segregated. Shots should have a seamless blend of live action and special effects. That is what would make the visuals magical. For instance, here is a cricket shot which may find excuse as being part of community activity. For the drama of the shot of a ball hitting the stumps (and coming out into theatre space) it would require a combination of elements - 1) live shot of the ball being bowled and batsman hitting it 2) CG generated ball taking the trajectory we desire 3) mechanical rigging for the stumps & bales to smash and scatter 4) pyrotechnics for particles to fly (motion slowed down adequately) 5) further particles added in CG so as to fly into the theatre space. Only in such combinations the magic works.

Also, for the 3D narrative to be effective, keying in & compositing of layers of blue screen live action shots have to be resorted to. This is done to workaround the problem of extreme parallaxes.

It is to be noted that 3D effects do not happen just incidentally or by accident. For shots to have positive depth (into the screen), they have to be specifically framed to evoke depth. Objects/ characters have to be positioned to define planes of perspective. Depth cues have to be incorporated in the framing of the shot – for example, side dollying. For shots of negative depth – off the screen shots or forced perspective shots, they have to be conceived at the scripting phase itself. Special teams have to be assigned in executing these during the shoot. They would have to use special riggings/ wire pulling to bring objects floating into theatre space. If it is a film shoot, in most cases these shots have to be taken during separate callsheets (2nd unit) such that it does not disrupt the flow of dramatic/ action narrative of a scene being completed.

Selection of colors for the foreground objects brought into theatre and the saturation of the colors they overlap in the background is very important. Same is the case for selection of artefacts, costume color. Only an artdirector with film 3D experience can advise on this. We have such artdirectors (along with scriptwriters, rigging experts, 3D printmedia personnel, CG modelling artists) who have shot 3D programs for our themed park.

If there are close-ups, they have to be planned before hand either with lessened intraocular or a cheated background (the background is placed close to the subject). Otherwise, eyestrain shall occur.

It is nearly impossible to take anykind of suggestion shot (over the shoulder shot) in 3D!!! The only way to achieve that is to take foreground and background subjects separately and compositing them in post. (Or one of them should be a computer generated image). If you notice, AVATAR is full of such shots. Hence it takes meticulous advance planning and preparation of elements compositing tabulations as in the case of special effects shots in 2D films.

My personal experience is that the production cost for a 3D film shall come to 2 to 2.5 times the cost if the film is shot flat (2D). For your budgeting, please take this yardstick. This is after you reduce cost by (1) cutting down on star value, (2) limiting the number of bracketed shots, (3) limiting the film screen time, (4) proper story boarding and even doing a complete previsualisation presentation for the benefit of your production team.

Advice on budgeting

It is understood that the director/ producer of a film in conjunction with the contracted editor/ cinematographer/ artdirector + costume designer/ CG house/ lineproducer (exec producer) shall do a full previsualisation of the final product. The 3D project consultants (in this case MRT) shall provide the services of their experts in these areas plus that of the stereographers to finalize such a blue print for the film.

A specified advance shall be paid to the consultants (say 25% of the total consultancy fee) for this exercise.

  1. The total cost of the film, the producer has to estimate if it were done in 2D. For doing the same in 3D, The yardstick shall be 2 to 2&1/2 times what it would cost in 2D. This is due to the extra time taken for every shot, extra lighting for holding a high aperture value to ensure maximum depth of field, 3D hardware, personnel, expertise etc; The 3D hardware components costing is as below. Equipment cost – approximately 3 lacs per day. This is for a) two cameras, b) 3D rig, c) master generator genlock sync & tc, d) For the Director & Cinematographer a HD Video tap linked to a 3D monitoring & projection system in the studio floor/ caravan trailor plus a 3D TV monitoring system with shutterglasses / iglasses on the outdoors. e) For the Stereographer a HD monitoring of discreet stereo images (left straight, right flipped) towards the convergence settings - on TVmonitors in the studio, on laptop (software/hardware assisted) for outdoor location. f) convergenge charts, focus charts, IR and Laser range mesuring instruments. g) freeze frame tap and frame transfer to laptop photoshop for checking offthe screen shots. h) two channel(leftimage/ rightimage) live keying facility for checking matte, CG shots.

i) interformat digital convertors, cables, connectors etc. h) Computer Applications - logging softwares for camera, audio, edit, asst director’s report, convergence, lensing parameters for the shootingspot laptop/s. Most of the items the consultants have in procession and/or can organize and provide. This is a budgetary estimate. For special shots, rigs would have to be adapted and components custom built. Please note that Pairs of cameras & matched lenses would have to be high end. If Digital, then Red One, Arri D21, etc/ for highspeed Phantom, Weisscam / sometimes even 35mm full aperture film cameras Arri/ Panavision (in which case, the images have to be scanned in). Lenses of the order of Cooke or Ultra prime.

  1. Costing for a digital postprod workflow would be for two image streams.

  2. For special shots that require specialised equipments (motion control, extreme high speed cameras, etc) as per the shot design, the hardware has to be hired. The general budget would in all probability have this margin for accommodating this.

  3. For CG, graphics, EFX, animation, matte shots, etc, the production agency contracted for the film shall execute the intended effects in 2D (as jointly decided in the peviz). The CG budget would reflect this quantum. The consultants shall take up the files, rendered layers (as the case may be) and with their own personnel shall execute the 3D part of the effect (the other eye camera passes). These effects have to be costed as per the design of each shot.

  4. Exhibiting 3D. It is in the scope of the 3D consultancy to offer all advices to the producer regarding a) making Filmprints for 3D, b) Encoding Digital prints for theatre servers, c) drawing up parameters for theatre selection, d) equipment selection for installing new cinema halls towards 3D, e) providing test/ alignment charts, Silver screen selection, 3D glasses selection, any shutterglass projection venues, etc. If any of the equipments or personnel have to be provided by the consultant, it would be at actual costs.

The consultancy cost for the 3D expertise should be budgeted at 5 to 7% of the production cost of a film project. This includes the services of a strereographer throughout the shoot.

The 3D consultancy cost for an Ad or a corporate film has to be budgeted for 20lacs for a consolidated 3day shoot. Any more days, it shall be prorata. The equipment cost for Ad shoot may be budgeted as 3lacs per day for a minimum 3 day shoot.

If special venue exhibition is involved. We shall be happy to assist you in putting up your machinery.

Selection of screening tools is very important. Two crucial things about a projected 3D image are 1) screen illumination 2) image resolution. Hence, depending on the screensize the projectors have to be selected and installed. It has been proven that dual stream, silverscreen, polorised (circular) passive glasses technique is the best (and sometimes the most cost effective method) for 3D imaging.

Depending on screen resolution and data rate, single or coupled servers have to employed. The encoding method used shall depend on this decision.

[We sometimes have used 60 frames per second playrate to project startling 3D. (A technique Swiss company Showscan has always used for its 2D special venue projects). That would mean the camera rate must be 60fps or above! This is useful only if you have fast moving visuals. ]

Audio system has to be 6.1 to enhance movement of objects in 3D space. Infact, the sound designer has to mix the program by seeing it in a 3D projection.

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