Stereo Video Production : HardwareScott Lawrence (formerly with Vuzix Corp.)
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Introduction
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Hardware
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Filming
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Interlace
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Edit
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Export
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View
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2.0: Table Of Contents
- 2.1: Integrated 3D Hardware
- 2.2: 3D Camera Add-ons
- 2.3: Build your own 3D Camera
- 2.4: Build your own 3D Preview Display System
2.1: Integrated 3D Hardware
There are a few very high end cameras that will let you produce 3D footage. Generally they consist of either two custom-modified camcorders with synchronized shutter systems. These cameras are excellent for producing high speed, high quality 3D content. They are generally mounted on a precisely calibrated mounting plate. They also are generally very expensive, but produce excellent results.
2.2: 3D Camera Add-ons
There are a few shutter systems on the market that consist of a prism and LCD shutter system that gets mounted in front of a standard camera. They hook into the video output of the camera to get their shutter sync.
These systems will turn on and off the shutter on the proper eye in precise sync with the interlaced video being recorded. These systems only work on analog video cameras, as digital video cameras (DV for example) have a delay in their video output with resepect to the CCD scanning. Modern DV cameras have HD modes which are incompatible with this as well. These systems also may not work well on old vidicon tube-based cameras, not that anyone uses them anymore anyway.
2.3: Build your own 3D Camera
The images and description in this section will guide you as to how we built the 3D filming rig that we use around here. While it won't be perfect for theatrical use, it is perfectly fine for casual or independent use. It is rigid, and works really well. This, combined with the processes described later in this documentation will be all that you need to produce your own 3D stereo content.
You may notice that with our system, it is not easily possible to geometrically align the imagery. Our studies have shown that as long as the 3D is viewable using our display system (see below), it is not necessary to precisely measure the camera alignment.
Many professionals will argue that the cameras need to either be exactly parallel with each other, or need to have a precisely measured amount of toe-in. We've found that we get the best results by having the cameras toed-in such that the subject is at the zero-crossing, where both cameras converge. This will produce imagery that goes "beyond infinity" but as long as the detail in the background is minimized, it is acceptable.
The materials and tools required for this project are:
- Two small DV Camcorders (We used Canon ZR800)
- 1" Square steel tubing - for the crossbeam
- two 4"x 1/4"-20 Lag bolts
- two 1/4"-20 wingnuts
- two 1/4"-20 metal washers
- two 1/4"-20 nylon washers
The cameras we're using. A Canon ZR800. It was inexpensive, at around $200.
The side showing AV output, microphone and firewire ports.
Long 1/4"-20 lag bolt, wingnut, fender washer, all of which go below the crossbeam, and the nylon washer and camcorder which go above the crossbeam.
Put the lower parts in through the bottom, then thread the camera into them.
Hand tighten the lag bolt into the camera so that it's relatively snug.
Then thread the wingnut up to the camera and tighten.
Showing both cameras installed on our crossbeam. You can use inexpensive 1" square metal tubing or wood. This one shown here is a part from our optics bench. It is not necessary to have it be as expensive or substantial.
Top view of two cameras relatively parallel with eachother.
Top view of two cameras toed-in substantially.
Front three-quarter view of the inexpensive 3D rig.
Rear three-quarter view of the inexpensive 3D rig.
This camcorder has a composition grid which you can see in this shot. It is helpful for aligning the two cameras without use of an external viewfinder.
Handheld shooting is easy once the cameras are aligned.
Shown here with a 6" IOD, both viewfinders are usable
With a 2" IOD, the viewfinders are not usable, and alignment is difficult at best.
Be careful that you don't block either camera while shooting.
At a 4" IOD, the right camera's viewfinder is not very comfortable to use, but good enough to get basic alignment.
The rig with our 3D preview display system made from two Vuzix AV230 units. It makes for much simpler alignment and filming.
2.4: Build your own 3D Preview Display System
Since the alignmnet of the 3D Stereo Camera can be imprecise, we have also constructed a preview display system so that we can see, at filming time, what the finished content will look like. It is also perfect for aligning our camera rig. By aligning it visually, we can be sure that the content we produce will not generate eye strain in the end user.
The materials and tools required for this project are:
- Two Vuzix model AV230 eyewear (AV920 will provide a higher quality image)
- Small Phillips screwdriver set (#0, #00)
- Fine soldering iron and solder
- Solder wick or a desoldering tool
- Rotary cutting tool
Notice: Doing this will invalidate the warranty on your Vuzix eyewear. You should not attempt this modification unless you know what you are doing. Spare and replacement parts may not be available.
Unscrew the two screws on the Vuzix AV230 to open it.
Carefully pop the front off. Some wires may catch on the front.
The front facia plastic, optics module and frame will separate, but be careful of the headphone wires.
The lead-in wires go through a gromit on the front facia plastic.
The temples can be easily pulled off of the tension springs.
The back of the optics module removed. Notice the two displays going into the single board.
Carefully lift the connector tabs to release the tension on the LCD display ribbon cables.
This connector is for the LCD backlights.
Gently lift up the outer bit to release the tension on the LCD ribbon cable.
Remove the LCD ribbon and backlight from one display. Prep the cable from a second pair of eyewear.
Just a close up to show how the screw holes line up with the rubber bushing inside.
A close up to show how the headphone wires are routed through the side notch.
And this is how they go back together. Be careful that these wires don't get pinched or routed in the wrong place.
When reassembling, first reattach the temples to the tension springs, then gently tighten the earphone wires.
Front face plate removed.
Gently snap it all back together.
Here we have the left eye driven from one board and cable, and the right eye driven from a different board and cable.
Close up.
As you can see, it will be tight to get it all in there.
Board sandwich. Somehow, nothing is shorting out. As you can see though, there will not be enough clearance with those extra connectors on the board.
The front plastics notched out to let the boards fit within the original device plastics, sort of.
Since there are now two wires coming out, we need to accomplish the strain relief externally with zip ties.
Nylon zip ties hold the cables in place. Some black electrical tape over the face will keep dust out.
Some further work is needed to streamline this.
Here it is hooked up to the3D camera. One eye is being driven by each camcorder, giving a perfect representation of the finished 3D stereo video media product.
The finished streamlined version.
Two boardsets installed in one case. Some plastic from the center of the optics module was removed to allow for the space needed.
Here you can see the plastics we're demonstrating with next to a production optics module.
You need to remove the honeycomb like section from the back. This makes space for the second board.
Material almost removed.
Material removed, needs some cleanup.
After cleanup.
Close up of the finished plastics.
Two boards are in place facing eachother.
Notice that the socktes for the backlight and LCD for the second display are removed. Audio inputs removed from the second board as well. White wires are power, which is necessary.
The bottom board has its left audio input wrapped around to the right. We're using one of the audio lines for the second video input. (Mono audio, stereo video)
The battery box with its extra pigtail on the right for the second video input.
Labels on the battery box so that I remember what is what.
Three screws hold it together with #0 + screws.
Battery box disassembled. The red/black audio pair is used for the second video input to the pigtail. Extra tape is around it to secure it in the box.
Notice the red/black lines cut from the J4 connector. Those are used for the second video input.
Fitting it all back in the battery box.
If you want to combine both inputs through one set of wires and one battery (as I have done in the later portions of this example, You may want to rewire it a little. I replaced one of the audio inputs to the AV230 and used that as the video input for the second display. The following table (which you could determine on your own - I'm not giving up any secrets here) explains which lines carry which signals;
- Black - Right Analog Ground
- Red - Audio Right Signal
- Tan - Left Analog Ground
- Green - Audio Left Signal
- Blue - Green LED (from upper board)
- Gray - Red LED (from upper board)
- White - Digital Ground
- White (Striped) - Power
- Purple - Video Analog Ground
- Yellow - Video Signal
This PDF shows the wiring modifications that I used to create the Integrated Dual hack above.
In English, I used the second audio wire pair (Red/Black) in the main wire for a second video input. The audio was then bridged on the primary board across both inputs, and power was run to the secondary board. The Red/Black pair from the main wire was then tied to where there Purple/Yellow video input used to connect on the secondary board.
This page is a part of the Yorgle Notebook.