(Frequently Asked Questions)
Q: How does 3D filmmaking work?
A: Most of us humans see life in 3D. That’s because we have two separate, distinct eyes that naturally create two, slightly different perspectives. In the brain, this small variance in image perspectives is interpreted as depth and dimension. In the world of 3D filmmaking, we replicate this process by using two cameras. One camera to represent the left eye and a second camera for the right eye. Then we sync, place the cameras on a 3D rig, align and offset the two cameras. We’re then able to film a subject, deriving two images with a slight perspective shift. When these images are overlaid in post, the perspective shift produces the illusion of dimension, or 3D. What’s miraculous about our human eyes is the ease, speed and accuracy at which they’re able to re-focus, converge, and shift from one object to another, delivering a beautiful 3D picture all in under a millisecond. It’s much more difficult to re-create these precise actions in a 3D filmmaking environment. But human eyes, although amazing, do have a few setbacks when it comes to stereo viewing.
Since the distance between our eyes is ‘fixed’ on our faces, as the distance to objects increases or decreases from us, our eyes can’t change their position, or perspective. For example, notice that mountains in the distance appear flat. This is because the perspective shift (distance) between your two eyes is fixed and slight, so that at such distances you see virtually the same image and therefore no discernable dimension. In such an instance, 3D filmmaking has an advantage over human eyes. Filmmakers are able to increase the IO (inter-ocular) distance. In this context IO refers to the distance from the center of one camera lens, or eye, to another. An increase in IO creates a greater shift in the image perspectives and thus accentuates the 3D effect. So when filming mountains at a great distance (miles away) in 3D, your two cameras may be 10-20 feet apart or more, depending on your shooting ratio and/or desired 3D effect. This ability to change the IO is the 3D filmmaker’s primary tool for manipulating dimension – depth and pop. Conversely, pushing two cameras closer together (decreasing the IO), diminishes the perspective shift, thus reducing the 3D effect. Beyond IO manipulation, stereographers (3D experts) can incorporate secondary tools like convergence (tow-in) and image alignment (xyz axis) to achieve a comfortable, eye-catching 3D images that ultimately serve the story. As a side note, when filming mountains in 3D at a distance, typically NO convergence (tow-in) would be used, but rather the cameras would be fixed straight ahead.
Q: Why do I need a beam-splitter (mirror) rig to film 3D, can’t we just mount two cameras side-by-side?
A: The short answer is – you CAN shoot 3D using two cameras mounted side-by-side. As a matter of fact, this is the preferred method for filming scenic 3D landscapes, wide shots and any longer focal lengths. But unfortunately, for shots where the focal length is about 25 feet, or less (medium and close-up shots), you need a beam-splitter, or mirror box rig. Why? Because objects filmed at closer proximities require only a slight or small perspective shift between both cameras to achieve comfortable 3D images. Put simply, your 2 cameras must literally share part, or most of the image area being filmed. Unfortunately, with a side-by-side setup the camera bodies “get in the way” and won’t allow your lenses to get any closer than about 5 or 6 inches, making 3D uncomfortable. Conversely, a beam-splitter rig allows the cameras to actually get on top of each other, sharing the same image area. In the simplest terms, beam-splitter rigs let one camera typically positioned horizontally shoot “through” a piece of optical-grade mirror glass -- while a second camera set perpendicular and vertical, films “off the reflection” on the front side of the mirror glass. In this posture the shift in perspective between the two cameras can be very, very slight. We highly recommend that your beam-splitter mirror glass be an optical-grade, very flat, very clear variety with highest-grade 50/50 coating. If your glass quality is in the least bit substandard (and most inexpensive mirror glass is) – your images will be unsatisfactory and your 3D images unusable as professional 3D.
Q: Why not use a dual lens camcorder to shoot stereoscopic 3D, like the Panasonic 3DA1?
A: The “fixed lens” nature of a dual lens 3D camcorder restricts the IO distance (it’s fixed) and therefore the control over the 3D effect. Rather 3D camcorders rely completely on camera convergence (tow-in) to manipulate the 3D effect. Convergence is typically set after the stereographer sets his or her IO. Convergence is the icing on the cake, so to speak, not the main course. So using a dual lens camcorder, limits the types of 3D scenes you can capture – no medium or close-ups, flat landscapes and doesn’t allow for things like polarizing filters or lens choices. So with camcorders like the Panasonic 3DA1, with a lens separation of about 3.5″ (70mm), you’re restricted (for comfortable 3D) to subjects between approximately 12ft (4m) to 40ft (12m). Beam-splitter rigs don’t have this same limitation as the camera separation can be adjusted all the way down to zero if necessary for objects directly in front of the rig. This is of major importance when you consider that most theatrical stereoscopic 3D productions use inter-ocular (IO) distances of between 1″ to 2″ (25-50mm) and shoot using high-grade lenses – something only attainable on a beam-splitter rig.
Q: How come your 3D rigs are so much cheaper than other company’s rigs? Do they really work?
A: Yes, not only do they work, but they produce high-quality stereoscopic 3D images. Just ask Sephora, Disney, Discovery, ESPN, Disney, NASA and a bunch of USC Film students. They’ve all captured high-quality, stereoscopic images using our 3D rigs.
Yes it’s true, our rigs are the most affordable, professional 3d rigs on the market today. Why? Because wherever possible, we use pre-existing aluminum materials in our rig construction. It makes sense to us and saves on manufacturing costs. We pass that savings on to you. Several critical parts, however, like our fully adjustable camera mounts (xyz axis, convergence and elevation), glass mounts, tripod mounts, etc. are custom machined and hand fit to function at the highest level. The overall result is a precise, rigid, black anodized aluminum frame - that’s nearly indestructible. We also don’t compromise on the optical-grade 50/50 beam-splitter glass, something that we ‘ve been perfecting with our vendor for three years now. Beware of using a Do It Yourself (DIY) rig. Why? Because you can’t get true optical-grade 50/50 beam-splitter glass. To do so requires ordering quantities of 20-30 units at a time. On the other hand, our competitors’ rigs typically utilize a wide variety of custom carbon graphite and aluminum parts. Few expenses are spared. The actual quality of the 3D images they produce isn’t any better than ours, but I will admit, some of their rigs look pretty damn cool.
Q: How easy is your 3D Rig to adjust and set up?
A: With the exception of 2 or 3 parts, our 3D rigs are shipped fully assembled. It typically takes less than 30 minutes to unpack the rig, attach a few parts and insert the mirror glass. The second phase is rig calibration. This is the process (about an hour) where the user gets to know the rig -- aligning frame, camera mounts and glass, to fit your specific cameras. Once calibration is complete, the rig can be ready to shoot 3D in minutes, from case to set-up, assuming you use the same cameras.
For everyday 3D filming, there are five principle adjustments on the rig to achieve image alignment and manipulate the 3D effect. Camera height allows you to adjust the elevation of the camera/lens height. Once set (thumb knobs) with particular cameras it’s unlikely to need further adjustment. Camera Tilt/Roll: This is the pitch, yaw and roll (XYZ axis) of each camera/lens and is done via four thumb knobs on one or both camera plates. Mirror Tilt: This can be adjusted to compensate for any camera tilt or lens centering errors and is done with two thumb knobs at the sides of the beam splitter box. Convergence: Allows users to adjust the tow-in point if you prefer to shoot converged. Again this is an easy to adjust using two thumb knobs. Inter-ocular (IO): This is the most frequently used operation, and needed to manipulate camera separation. Our beam-splitter rigs offer IO distances varying between 4” to 6” and operate using a variety of simple methods.
To be real - to get completely familiar with the working of any 3D rig, and be capable of shooting quality 3D - you need professional, hands-on instruction. You can’t get it via online research. It’s for this reason alone that we offer professional, hands-on 3D training workshops. They’re an excellent way to get started. Over the past several years our veteran stereographers have taught hundreds of participants to shoot good 3D. See the ‘3D Training’ page for locations, dates and registration information.
Q: How easy is the rig to transport?
A: Fairly easy, depending on the particular rig you choose. We have several, but All of our beam-splitter rigs breakdown for transport and/or shipping. Or if you prefer, you can pack a rig in a single pelican style case. We travel with them all the time – Africa, South America, even Hollywood.
Q: Do the cameras need to by gen-locked (synchronized)?
A: Yes - you will need to have at least one gen-locked camera to sync it to another camera, or use LANC equipped cameras with a 3D LANC controller. If you don’t gen-lock your cameras, it’s very likely that some of your frames may be out of phase with each other. Please understand that you CAN NOT correct this phenomenon in post and it may render all, or some of your footage useless in 3D. In such a case, you’d have to use the 2D version. The bottom line is, if you’re shooting a professional 3D you need to use two identical cameras that gen-lock.
Q: What cameras can I use on the rigs?
A: You can use almost any pair of cameras that physically fit on a rig (we have several models) and gen-lock. Currently, the most popular 3D camera choices are Arri Alexa, Red One, Epic, Sony EX3, F3, F950, Canon XF305, XF105, H1, 5D, 7D, Si-2K, any DSLR and many others.
Q: What is the ‘Field of View’ and what lenses can I use?
A: Most of our rigs feature wide-angle mirror boxes and an adjustable mirror centering option, not found on other rigs. This feature allows our rigs to accommodate a wide variety of lens lengths and sizes. More than most other rigs. If there is an image discrepancy, or any box interference, cinematographers can easily trim the image edges in post.
Q: What is the light loss?
A: With a true 50/50 beam-splitter mirror each camera only gets half the light. Therefore the light reaching each camera is reduced by approximately 1 f-stop. It is impossible to design a mirror rig with less loss, the light is after all being divided by half. Be wary of any rig with anything other than a 1 f-stop per camera loss.
Q: Can you teach me how to use the rig?
A: Yes. We offer a popular, monthly 3D Training Workshops in Los Angeles and San Diego. These are intensive, hands-on 3D filmmaking classes where veteran stereographers teach you how to shoot professional style 3D. As a matter of fact, over the past 3 years we’ve conducted more 3D training workshops than any other source. Check our website under ‘3D training’ for workshop times, locations and registration information.
Q: Are your 3D rigs good enough to film a movie or 3D TV with?
A: Absolutely. Our 3D rigs are designed to align and manipulate 3D images, while locking two cameras into position. And of course, the beam-splitter glass quality is of major importance. The rest is dependent upon the cameras you choose and your moviemaking ability. For the best results, however, we recommend using the Arri Alexa, Red One, Epic, Sony 950, F3, or other high-end HD cine-style cameras. To date our rigs have been used by Discovery 3D, ESPN, Disney, Honeywell, NASA, students at USC Film School, just to name a few.
Q: Can I zoom my cameras with your rig?
A: Yes, but you might not want to. First you will need to find a way to synchronize the two zoom lenses. This can be done with most newer 2/3” digital broadcast zooms. Fujinon now has special matched pairs of lenses available for 3D applications. But it’s difficult to use with smaller compact camcorders, as lenses do not normally zoom in sync. You should be aware that as a zoom lens changes focal length, the center point shifts slightly which will misalign both cameras. Even more importantly, is that zooming “in and out” in 3D, is not a pleasurable effect for the viewer. A zoom foreshortens the image, while the 3D depth increases. In reality, it’s a funky visual effect that takes the rattles the viewer out of the picture. It’s best avoided if at all possible. We found it’s best to shoot your master shots, then push in, re-frame and shoot your medium and close-ups. We recommend shooting “in zones”, where the camera remains equidistant from the subject, but moves in a variety of side-to-side fashions.
Q: Is the mirror glass delicate?
A: No more than any other piece of 3mm glass. The mirror is an optical-grade, clear glass, so drop it and it will break. When filming 3D - we always take a spare piece of mirror glass with us. If your single piece of glass breaks, without an extra - your shoot comes to a halt.
The high-grade coatings on the surface are to precise 50/50 specs, so gentle cleaning is not an issue provided you follow our cleaning instructions included with the rig. In addition the mirror box and frame assembly does give the mirror some protection during transit and everyday use. Treat it gently and it should not break.
Q: Why do you offer several 3D rigs to choose from? Which 3D rig should we use?
A: It’s our belief that no one rig can fit all the needs of production. Therefore, we offer a variety of 3D rigs – big, small, top mounted, bottom mounted, custom and more. This gives the client the right options to match their production needs. Here are some examples of what our rigs do.
All of our rigs are optimized for use with CMOS sensors. These sensors scan from side-to-side. In this regard, we have carefully chosen camera positions (both top and bottom designs) that eliminate any “rolling shutter” effects that might otherwise be present. Some other “top” configured rigs have the camera in the wrong orientation and therefore exaggerate this “rolling shutter” effect, rendering much of the footage un-useable. This is especially true when the rig is panned or if anything moves through the shot due to the skew of the two CMOS cameras going in opposite directions.
For example, our large 3D-BS PRO RIG is structurally re-enforced to easily handle large ENG and CINE style cameras. A rig like this is necessary when shooting with the Red One, or Arri Alexa. Our smaller rigs and others on the market that use aluminum rod systems can firmly support two fully loaded Red’s.
Top configured cameras can be top heavy if your cameras are heavy, but provide greater light dampening in some situations and set-down easily with simple foot pads.
Bottom configured camera rigs work well with steadicam devices and have a low center of gravity, but on the negative, they prove problematic when filming low angle or specialty shots and besides a tripod, they don’t set down easily. They can also experience overpowering light intrusions when filming over reflective surfaces, such as water or glass.
It’s important to give thought to your production needs and choose based on those specs. To find the proper 3D rig for your cameras we’ve created a “suggested cameras” list on each page. This will tell you which cameras fit easily onto the rig. If you have more concerns related to your specific production needs, please don’t hesitate to contact us.
Q: Should I use a 3D monitor when shooting 3D?
A: Yes, you should be monitoring (watching) everything your shooting in real-time, stereoscopic 3D. Filming in 3D without using a 3D monitor – is like driving blindfolded. For that reason, we have a plethora of easy to use, affordable 3D monitors and multiplexors to choose from. A multiplexor is a device that combines the signal from 2 cameras in real-time, then translates them into a single 3D image – usually anaglyph or polarized. The monitor you select is dependent on several factors. Are you shooting in the field without a 120V power source, or in studio? In the field, we recommend a fully contained 12V 3D viewer system. In the studio we recommend a multiplexor and large screen HD montor. Is your project being created for YouTube, TV, the big screen ? If so, we recommend the largest monitor possible to accentuate any errors.
ABOUT 3D FILM FACTORY
Located in sunny San Diego, California, the 3D Film Factory is the leader in professional, affordable 3D camera rigs and real-time 3D viewing systems. In addition we provide a host of 3D production and post production services, including 3D gear rental, stereographers ‘for hire’, 3D exhibition solutions, as well as, hands-on 3D training workshops. Clients include ESPN, NASA, Disney, HD Cinema, Pinewood Studios, Honeywell and many others.
The 3D Film Factory is dedicated to providing professional, affordable stereoscopic 3D systems that allow our customers to create high-quality 3D images for a fraction of the cost of competitive systems.
Robin Laatz President
Shawn Gilmore Director of Operations
Keith Driver Director of Stereography (DOS)
Victor Lou Lead Stereographer / Cinematographer
Chris Wright Stereographer / Camera Operator
Nate Tieman Assistant Stereographer / Red Camera Operator
John Blythe Assistant Stereographer / Camera Operator
Stephen Barr 3D Video Tech / Camera Operator
Joe Richardson 3D Editor & Post Supervisor
Bob Cooper 3D Production Assistant
About 3D Film Factory
Since 2008 we’ve been the leader in professional, affordable 3D camera rigs and 3D production monitors, as well as a full-service 3D production company that offers 3D rig rental, stereographers ‘for hire’, and 3D post production, as well as, 3D training workshops and seminars. Our veteran stereographers are some of the best in the World and they’ve filmed stereoscopic 3D projects for major clients on almost every continent. Our clients include Disney, ESPN, NASA, Discovery Channel, Honeywell, USC Film School and many others.
Developed by award-winning filmmakers and veteran stereographers, our line of 3D beam-splitter (mirror box) and side-by-side rigs offer filmmakers a viable alternative to a high-priced, behemoth 3D rig, costing ten times as much and more. A 3D Film Factory rig is lightweight, precise and features unlimited alignment and XYZ axis control, allowing users to create perfectly aligned 3D images.
“Since 2008 our goal has been to proliferate 3D to ALL filmmakers, not just the James Camerons of the World“, said company operations manager Shawn Gilmore. “Our goal is to make a quality 3D rig that every filmmakers can afford. We're succeeding, because today our 3D rigs create fantastic stereoscopic images and they’re affordable.”
The 3D Film Factory’s rigs are designed to accommodate a wide range of professional HD cameras, including Red One, epic, Sony F3 & EX3, Canon 305’s, 105’s & Canon 5D, Arri’s Alexa, and a broad range of camcorders, compact HD cameras and all the DSLR cameras.
The beam-splitter rigs (mirror box) are fully adjustable, allowing users to have total control over convergence settings (1° to 5°), inter-ocular (camera-to-camera) distances (0” to 6”) and complete yaw, tilt and roll (XYZ axis), for perfect 3D alignment. The black anodized aluminum frames are virtually indestructible, yet completely modular. The side-by-side systems are easy-to-use, fully adjustable and offer inter-ocular distances of 30” or more.
At the center of the 3D rig is the mirror box with its optically engineered, 50/50 beam-splitter glass. It’s fully encased in high-grade, specially formulated foam plastic, that’s light-dampening, detachable and cooler than sheet metal or carbon fiber boxes. Finally, the entire rig readily attaches to most professional tripod heads with a simple aluminum tripod adapter (¼-20 & 3/8- 16 screws).
The result is the World’s most affordable, professional line of stereoscopic beam-splitter and side-by-side rigs. Together they make 3D filmmaking precise and amazingly simple. When combined with a 3D production monitor, cinematographers can capture extraordinary, eye-catching 3D images for a fraction of the cost of other options.