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The trouble with using hyper-stereo is that scenes with gigantic objects in real-life may appear as 

small models.

 

 This phenomenon is known as 

dwar

fi

sm

.

 

 The opposite happens with hypo-stereo, 

where normal sized objects appear gigantic. (

gigantism

.)

If one attempts to shoot with two cameras con

fi

gured in a side-by-side stereoscopic mount the 

smallest interaxial distance available will be the width of the camera.  In most cases the width of the 

camera will be around  6 inches (as with the XF305.)  This might seem like a big limiting factor, but 

other specialized equipment is available to achieve small interaxial distances with almost any sized 

camera.   (More on that a in the “Selecting your Gear” segment.)

Viewing 3D: Passive Polarization, Active Shutter Glasses, Anaglyph & Autostereo

There are three basic types of glasses used for presenting stereoscopic 3D material.

 

 In most of the 

theatres in North America the common method is 

passive polarized glasses

 with either circular or 

linear polarizers.

 

 There are consumer and professional HD 3D monitors that use the same passive 

method.  However, the majority of the consumer 3DTVs on the market now use some form of 

active 

shutter glasses

 to 

fl

icker the left and right images on and o

 in time with the television at a frequency 

of 60, 120 or 240Hz.

  

 

Autostereoscopic displays

 use lenticular lenses or parallel barrier technologies to 

present stereoscopic material without the use of glasses.

Anaglyph glasses

 will work with almost any display but use color 

fi

lters to separate the left and right 

images.

  

 The most common con

fi

gurations are red/cyan, blue/amber, and green/magenta. 

THE QUICK MATH & SOME RULES TO REMEMBER

Stereoscopic Parallax Budget (sometimes called Depth Budget) vs Depth Bracket

The Depth Bracket of your scene refers to the actual distance between your closest object in the 

frame and the furthest object.  The Parallax Budget refers to your calculated maximum positive 

parallax and desired maximum negative parallax represented in percentage of screen width.  For 

example if I determine through a simple calculation that my positive parallax should never exceed 

0.7% of screen width and I have determined that my negative parallax should not exceed 2% of 

screen width, then my total Parallax Budget is 2.7%.   The Depth Bracket must be able to be squeezed 

into the Parallax Budget.  There are many advanced algebraic formulas available to determine the 

proper interaxial distance to achieve this, but are beyond the scope of this white paper.

Native Parallax for 

fi

nal display size

The native parallax for a given screen size simply refers to what percentage of screen width will equal 

the human interocular.  If you are using 2.5 inches as the baseline interocular and you know your 

presentation screen will be 30 feet wide (360 inches) then just divide 2.5 by 360.  

2.5

 

÷ 360 = 0.007 

XF300/305 Whitepaper                

   

 

 

       

   

 

 

   Stereoscopic 3D

Tim Dashwood

6

Содержание XF105

Страница 1: ......

Страница 2: ...scopic depth It sounds simple enough but the first thing any budding stereographer should learn is some basic stereoscopic terminology These few terms may seem daunting at first but they will form the basis of your stereoscopic knowledge TERMINOLOGY Stereoscopic 3D a k a Stereo3D S 3D or S3D 3D means different things to different people In the world of visual effects it primarily refers to CGI modeli...

Страница 3: ...ge Try this Hold one finger next to your ear Now stretch your other arm out straight and hold up another finger Now bring your two fingers together and touch the tips together Is was easy right Now repeat the same procedure but close one eye Were you able to touch your fingers together on the first try Now you know how important binocular vision is at close range When we look around at objects at ...

Страница 4: ...rge on it creating a single image of the pen What you may not immediately perceive is that everything behind the pen appears as a double image diverged Now look at the background behind the pen and your pen will suddenly appear as two pens because your eyes are no longer converged on it This double image is retinal disparity at work and it is helping your brain determine which object is in front o...

Страница 5: ...ations on our retina to create parallax separation stereoscopically recorded and displayed objects will appear to have different horizontal offsets parallax depending on their depth in the scene If an object has no perceivable amount of parallax then we consider it to appear on the screen surface just as the star in the illustration This is why converging on an object will make it appear to be at th...

Страница 6: ...copic rig and it will be tweaked ever further in post production through the use of 3D mastering software Ortho stereo Hyper stereo Hypo stereo As mentioned earlier the average interocular separation of human beings is considered to be about 65mm 2 5 inches When this same distance is used as the interaxial distance between two shooting cameras then the resulting stereoscopic effect is typically kno...

Страница 7: ...r parallel barrier technologies to present stereoscopic material without the use of glasses Anaglyph glasses will work with almost any display but use color filters to separate the left and right images The most common configurations are red cyan blue amber and green magenta THE QUICK MATH SOME RULES TO REMEMBER Stereoscopic Parallax Budget sometimes called Depth Budget vs Depth Bracket The Depth ...

Страница 8: ...ut does the 1 30 rule apply to all scenarios No the 1 30 rule certainly does not apply to all scenarios In fact in feature film production destined for the big screen we will typically use a ratio of 1 60 1 100 or higher The 1 30 rule works well if your final display screen size is less than 65 inches wide your cameras were parallel to each other and your shots were all taken outside with the back...

Страница 9: ...n ranges helicopter shots etc Side by Side Rig In order to shoot subjects in close range within 15 or 20 feet you will require a beamsplitter rig Beam splitters use a 50 50 or 60 40 mirror similar to teleprompter glass that allows one camera to shoot through the glass and then other to shoot the reflection The interaxial can be brought down to as little as 0mm 2D with beamsplitter rigs There are o...

Страница 10: ...m fisheye lens adapters because the distortion will cause many geometrical disparities Shooting in the zoom range of 4 1mm to 10mm with the XF series cameras is recommended for beginners SECTION 2 SHOOTING 3D WITH PAIRS OF XF105 OR XF305 This section describes the technical intricacies of configuring a pair of XF105 or a pair of XF305 cameras with firmware v1 0 2 0 or newer to work together to cap...

Страница 11: ...enlock input signal Continue to the next step for GENLOCK SYNCING the cameras TIMECODE SYNC FOR XF305 CAMERAS Connect a BNC cable from the TC terminal on one camera to the TC terminal of the other camera Set the TIMECODE MODE on both cameras to FREE RUN You can set a custom preset timecode on your designated master camera first On the master camera enter the TC UB Setup menu and then Timecode subm...

Страница 12: ... Term menu to set the input to GENLOCK input signal If you intend to shoot 24P then signals from a tri level sync generator like AJA s Gen 10 will need to be input into the GENLOCK port on both cameras This is required so that the pulldown patterns on the two cameras sync perfectly With either method you should ensure that the horizontal and vertical phase in the genlock menu of the slave camera i...

Страница 13: ...er camera choosing its own white balance focus or exposure Other Menu Function LCD Display Settings The following menu items refer specifically to the XF305 and some items may be located in a different sub menu in the XF105 Navigate to LCD VF SETUP CUSTOM DISPLAY OBJECT DISTANCE to ALWAYS ON Set LCD VF SETUP CUSTOM DISPLAY ZOOM POSITION to ALWAYS ON Set the OTHER FUNCTIONS CUSTOM FUNCTION OBJ DIST ...

Страница 14: ...amera for each frame and therefore will be a visual disparity Using Scan Reverse function to rectify mirror image for reflected camera If you are using a beamsplitter rig you may choose to undo the flipped or flopped image in the camera that shoots the reflection from the mirror This can be done easily within the XF105 or XF305 by selecting the CUSTOM FUNCTION menu and then the SCAN REVERSE REC su...

Страница 15: ...tion in a beamsplitter rig The tops of the frames must match so there is no rolling shutter disparity between the sensors If the mirror in your rig faces the ground and the upright camera mounts underneath then the camera can be mounted on the plate normally If your mirror faces up and the upright camera points down then the camera must be mounted upside down so that the top bottom orientation of ...

Страница 16: ...the images of the two cameras It is best to use a left right signal muxer to see the camera images superimposed or use a professional stereoscopic monitor that can accept left and right HD SDI inputs If you have aligned your rig as closely as you can get it you can take it one step further within the camera and utilize the LENS AXIS SHIFT to tune out vertical disparity or converge on any point Jus...

Страница 17: ...tailing advanced techniques for shooting posting and distributing stereoscopic 3D Remember stereoscopic 3D cinematography is a craft that can takes years to master and is a craft where even the experts are still learning new techniques As the popularity of S3D continues to rise there will by many demands on inexperienced videographers to provide stereoscopic services It is important to remember th...

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