Tag Archives: 3d

Shooting 3D with 2 Cameras and Synchronisation (Camera Rigs)

It is important to understand that no matter how much you slip and slide the clips from you cameras in the edit suite timeline to bring them into sync, if the images captured by the two cameras sensors are not in sync, you may have some big problems. Even if you press the record buttons on the cameras at exactly the same moment, they may not be running in sync. In the edit suite you can only adjust the sync by whole frames while the cameras may be running half a frame out and this can be impossible to correct in post production.
Remember that from the moment you turn a camera on it is capturing frames. When you press the record button the recording doesn’t start instantly, but at the start of the next full frame, so the synchronisation of the camera is dependant on when the camera was turned on and how long it takes to start working, not when you press the record button….. Unless you have Genlock, which overrides the cameras own internal clock and matches it to an external reference signal, forcing the camera to run in sync with the sync source which can be the second camera or a sync generator.
It is possible to shoot 3D with non-sync cameras, but any motion in the scene, or camera movement such as a pan may lead to strange stereoscopic effects including distortion of the 3D space, un wanted depth changes and moving objects appearing to float in front or behind where they should really be.
This doesn’t mean that you can’t use a non sync camera, just that it is less than ideal and it’s use will limit the kinds of shots you are able to do.
If you don’t have genlock a further option is to use a pair of Canon or Sony camcorders with LANC control. It is possible to get special LANC controllers such as LANC Shepherd or the controllers I have listed below:
These work with most camcorders that have a LANC port or AV/R port and provide good sync for periods of up to around 15 minutes at a time. To reset the sync the cameras must be powered off and back on. They work by synchronising the start up of both cameras and then measuring the sync error. The sync won’t be perfect, but it will be good enough for most 3D applications. However as there will always be slight variations in the master oscillators in the cameras, over time the sync will start to drift apart. The controller will tell you how far apart the sync is and when it becomes excessive you will need to re start the cameras to bring them back into sync, typically you get between 10 minutes and 20 minutes of useful synchronisation.

Just how big is the 3D market?

As you walked around the BVE show in London last week you could not help but notice that just about every stand had some kind of reference to 3D production. The impression given was that 3D is here, it is going to be huge and everyone needs to be able to shoot in 3D. But is this really the case? Certainly there has been a big increase in the number of 3D movies produced in the last 18 months and Avatar is now the largest grossing movie ever made, much of the profits coming from 3D screenings. Sky TV in the UK are starting a 3D TV channel later in the year and Discovery, ESPN and others have announced their intentions to launch stereoscopic channels. To add to all this the TV manufacturers are also bringing large ranges of 3D TV’s to market.

But before you all rush out and spend large sums of money on expensive 3D camera rigs you need to look more closely at what’s going on and consider who will actually want to watch 3D. Now I am a fan of 3D, don’t get me wrong and I do believe that 3D is here to stay, but as I see it, until display technology finds a way to eliminate the need to wear special glasses 3D is going to be reserved for special events, movies and spectaculars. Lets face it who’s going to want to have to put on a pair of glasses after a hard days work, just to watch the news or a soap. This is supported by Sky’s recent 3D seminar where they stated that they are only looking at showing 4 hours of new 3D programming every week and the only things they are looking for are movies, major sporting events, special events and one off, mega specials – “planet earth” type big budget docs. The rest of the week will be repeats and re-runs. So, in the UK it’s likely that there will be a couple of OB trucks kitted out for 3D for sports and other events filing a couple of hours a week leaving just two hours which will be split between docs, specials and movies.

Now Sky 3D won’t be the only outlet for 3D in the UK. There will be some corporate productions with budgets big enough for 3D and there will be a market for a few on-demand specialist channels and 3D BluRay’s and DVD’s but the really big market will be the 3D games market. Even so for most production companies, 3D could be an expensive mistake. Investing in expensive 3D rigs, pairs of cameras, 3D production monitors and edit systems won’t be cheap. In addition there is a whole new set of skills to be learnt, shooting 3D is very different to 2D. Perhaps (sadly) the real future of 3D TV lies not with true 3D capture and filming but with clever boxes like the JVC IF-2D3D1 2D to 3D converter which can take existing 2D material and convert it in to pretty convincing 3D for the price of a single pro camcorder. It may even be that one day all home TV’s will contain a similar converter and you will be able to watch whatever you want in Pseudo 3D at the press of a button.

So back to the original question, how big is the 3D market? Well I think it’s actually pretty small, probably best left to a few specialist production companies or 3D consultants and  facilities companies. Certainly lots of 3D TV’s will get sold to affluent techno geeks and home cinema enthusiasts, but lets face it, HD was a hard sell and you don’t need glasses for that.