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Do we want it? 3D Cinema,

Recently I was at the Australian Movie Convention in Queensland. One of the more interesting topic of the show was the industry push to 3D cinema. Two players in this technology where out to show of 3D. Let me tell you some interesting news..

RealD and Dolby, new to 3D, where there in force to show of how 3D cinema can be amazing to experience.

I saw both. Both where very good. One, however, was far better in my opinion.

Let me first give you a brief description of the technology and its plus and minuses.

RealD is the market leader. Slated to have over 1000 sites installed in the US by around October. RealD use the traditional (circular) polarization filters. A common filter used in sunglasses to cut glare. As such they are cheap to offer as a through away set of glasses when you enter the cinema. RealD requires the use of a SILVER SCREEN.

There are many different forms of polarizing lenses. Good sunglasses, which cut glare (Glare light is partly polarized), come with a typical straight polarization. A good way to spot them is if you hold them up to another set of polarized filters and rotate the angle between them. You will notice, at a specific angle, most of the light is cut out. Also many flat panel screens, for example Plazma displays, have a polarized sheet over them to cut glare. (Ever walked into a shopping mall and seen plasmas on there side showing adverts, and wonder why you can hardly see the picture…. take your sun glasses off).

When looking through two straight polarized lenses at the same angle, there is very little difference in light level. If they are at right angles (90 degrees) most of the light will be blocked.

Circular polarizing lenses work at ANY ANGLE. You usually haver a right or left circular polarization. As such, if you look through a right then left polarization filter, near all light will be blocked.

While using cirular polarization glasses on the audiance, the Digital projector has a special filter placed in front of it. This filter is an electric left to right circular polarization filter which is timed to switch between left and right as the images being projectoed is switched between left and right.

As such, in the end, you get each eye seeing a different picture. The 3D effect.

Finally, the big let down of polarization 3D. You need a SILVER SCREEN.

A silver screen is not a typical hi bright cinema screen. It has a metallic of mirror element in the surface. This is REQUIRED to keep the polarization effect on the light bouncing of the screen. If it is not a silver screen, the image looses the polarization effect and therefore looses the left and right eye separation.

Now the big issue here is. SILVER SCREEN look terrible. They either have a HOT SPOT as acting partly like a mirror, you are looking directly back into the projector light source. OR. They have this dirty non-flat finish that makes nothing look white. At best, it is the uneven dirty grainy white.

It is due to this that SILVER SCREENS are not DCI compliant. (DCI being the new standard recommendations for hi quality digital Cinema.)

Dolby use a high tech version of the traditional RED and BLUE paper glasses of the original 3D days. The difference is that it drops out half the colour from each eye. Not the full Red or Blue colour like the old school 3D glasses. There is no other application in the world that uses this type of filter. Ad the fact they are hard to make. They are VERY expensive.

The filter used by Dolby is quite complicated, but I will try to explain. Imagine we have Red, Green, and Blue bouncing of the screen. We then equate this to Red=1, Green=1 and Blue=1. What the Dolby glasses do is cut each colour in half. So, for example, on RED. One eye sees RED from 0 to 0.5 and the other eye sees RED from 0.5 to 1. This is done for each colour. In the end each eye sees each colour, but only HALF the dynamic range.

Its a little more involved then this but it gives you the idea. And let me assure you, the colour on screen per eye did not appear less vibrent then normal.

In the projector, a 2 segment spinning wheel using these filters is installed. Like a single chip DLP projector, but in this case, spinning at a rate to match the frequency for left and right images. The result is the left and right eye seperation and a 3D image.

The big PLUS with the Dolby implementation is that it uses a typical hi-bright screen, which is DCI compliant and looks great.

The big minus is the cost of these filters required in the patrens 3D-glasses. Currently at best, a $50 price tag. That is a lot for sometihng that is going to walk out the door on a regular basis. However, Dolby say they are gearing up for hi run, inexpensive manufacturing. Not holding my breath. These filters are complex in nature and as such, complex/expensive to manufacture.

A few more notes. Both systems need very BRIGHT/big and expensive projectors. You drop a lot of light cutting out an image our for each eye.

Also note, this is not new technology or ideas. Its just old ideas applied to the new digital equipment.

Both technologies are just as at home with two projectors projecting on the same screen, rather then one projector projecting two images taking advantage of new technology to archive it.

Now you have an understanding of the technology, I would like to give my opinion on the results.

Before I continue. Due to the nature of 3D, many people see if differently. Some people take quite some time to become accustom to it or even see a 3D image, while other see it straight away. Some are more sensitive to artefacts produced by the 3D experience.

Both systems look great, however, I found that RealD was more annoying to me.

A Major problem with 3D is that, to get the 3D separation, each image has to be on different parts of the screen. As such, when a 3D image moves out of shot, one eye’s image moves out of shot before the other. Ie, so the 3D effect breaks up around the edges. And the more 3D an image is, the more extreme this breakup. I find this VERY distracting and my main annoyance with 3D.

Out of the who systems. I found Dolby handled this the best. RealD, when going out of shot, the image for the eye still in shot appeared to strobe or flash. I could see this giving me a headache after a while.

Dolby, however, appeared to go out of shot and the image seemed to go a little more green or red. However, no strobing and less annoying.

One conclusion I took away from this, being in production,is that 3D, done well, has a lot of limitations. The idea would be to avoid these 3D artefacts, however to do that, you need to avoid letting objects that are extruded a lot, from leaving the shot or moving to far from the centre of the screen. This explains why IMAX has been so successful with 3D. As your peripheral vision is mostly covered, you do not see this 3D artefacts to any great degree. However, I feel this is the main reason 3D has come and gone in the past, and is most likely to do again.

Content from different sources where shown. The U2 concert was quite entertaining to watch. But at the end of the day, I personally did not think that 3D was anything more then a good whisky you bring out now and then, but we dring beer every night and we are happy with it. In real terms, the jump in quality on screen from going to 2k clean show after clean show (Film degrades quite fast), makes the image more 3D then 3D does.

Perception of reality is not 3D, but detail. Anything more then about 30 meters away cannot really be perceived as 3D anyway. For example, the Sports shot in 3D, to me, was not worth it. Obviously most is shot from a long way of, so they have to really push it to get any separation and then its less real then a high resolution flat image in some way. (Because to us we only see it flat at that distance)

Don’t get me wrong, I am happy to see 3D coming to my cinema, however, do not expect 3D to become anything more then the occasional party trick which suits specific content.