chris cunnington

The song ‘Get Up’ has been nominated for a 2013 Annie Award, to celebrate this nomination Triggerfish Animation Studio decided to shoot a music video. I was asked to head down to Digital Forest Studio on the day of the shoot and get some background photographs and video. This is the result!

Composer: Bruce Retief
Vocals: Zolani Mahola
DOP: Chris Cunnington

Equipment Used:
Canon 600D
18-55mm Kit Lens
50mm f1.4 Lens
Manfrotto MonoPod

Shot on location at Digital Forest Studio in Constantia, Cape Town

Final Music Video

A few months ago I wrote a post about Stereoscopic Depth Compression, the fact that our binocular vision and ability to judge depth reduces over distance. This phenomenon happens in real life too, and is not restricted to 3D Cinema, although in cinema it can often be exaggerated by using smaller interaxial settings. Due to this effect our three dimensional brain is forced to switch to the classic monoscopic depth cues to gather depth information from the frame. I have heard it said that 90% of a 3D films depth is actually based on the classic 2D depth cues. Cinematographers have had years to develop their methods to portray depth within a 2D cinema frame and as stereographers we should use that as our springboard to adding more depth.

So what are some of monoscopic depth cues? Well, many are based on the effects of perspective which I will not include in this list. So imagine all this was happening on a 2D orthographic level.

Relative Size

We as humans have developed a set of size expectations. A matchbox is small, a human is average and a building is big! So if we see a man standing next to a building, and his head is inline with the top of the building, our first assumption is that the man must be closer to the camera! Obviously our second option is to assume that he is a giant, but first we assume a physical reality exists.

Texture Gradient

If we have a repetitive texture created by objects, or scene elements (bushy landscape, etc) as those objects get further from the camera they will appear smaller, effectively following perspective. If the objects are similar in shape, your brain will assume they are further away.

Colour

Hue - Warmer colours advance & cooler colours recede.

Saturation - As you reduce the saturation of a colour it will appear to recede in your scene.

Occlusion

Its a big word, but its pretty simple. Basically if you see a bush in front of a house, it is occluding your vision of the house, then clearly it is in front of the house. If we were to move the bush so that it is occluded by the house, then your brain tells you it must be behind the house.

Motion

Two forms of motion allow our brains to see or assume depth. The first is based on our Point of View. Imagine you are sitting on a train looking out the window, near objects will be moving faster, or have a greater horizontal parallax, than those on the horizon. This illusion is used a lot in 2D side scrolling animations or games to this day. The second method is based on the objects speed. If we remove the movement from the viewer or camera, as in the first example, and use a static camera we are able to judge distance & scale based on the speed of an object. For example, an airplane in the distance appears to be moving very slowly, vs a airplane that fly’s directly over our head.

Depth of Field

Objects will often soften as they advance or recede with in the focus of a shot. This classic use of camera lensing has become a standard in the language of film, and viewers fully understand the depth cues created by depth of field.

Further Reading:

• Depth Estimation using Monocular and Stereo Cues
• Photokaboom Tips > Depth
• Monocular Cues in Depth Perception

Finally able to show some the of amazing work being produced here at Triggerfish on our second feature film ‘Khumba’. The images were released on the Kunjanimation website earlier this month and now its time to share the love!

The film is currently still in production, yet these images sure give you a glimpse into the amazing world the Triggerfish team has created! Be sure to find Khumba on facebook to keep in the loop regarding production and its release dates!

This post was originally planned to be about the setup and use of Multi Stereo Camera Rigs, but as I began to type I realised I needed to fully explain Stereo Depth Compression. The reason we resort to MultiRigs in the first place! The fundamental nature of human stereo vision only allows us in real life to determine stereoscopic depth up to roughly 6 meters away from us. Most optometrists will test your long distance vision by projecting patterns on the wall roughly 6 meters in front of you. Beyond the 6 meter mark begins a process I like to call ‘depth compression’, effectively an exponential fall off of perceivable depth recognition. It finally ends at a point where we cannot determine depth based purely on stereo vision but instead we switch to using methods such as distance haze, scale of objects, and object occlusion (an object behind another or not). Our brains are pretty impressive when it comes to tricking us into thinking we can perceive depth when we actually cannot.

Now because I work in a digital environment where everyone talks in pixels 1920 or 2048, etc… I also measure my stereoscopic depth in pixels. Many stereographers talk about a percentage deviation, I work on a pixel deviation or separation. This separation measurement is the difference between two matching pixels on opposite left & right frames. See my post ‘Mechanics & Mathematics of Stereoscopy‘ regarding this calculation. So what, does 1px represent 1 meter in the real world? Not quite, as you saw in my original post we have a limited number of pixels (14px) to represent the entire depth of the shot. Many stereographers including Phil McNally of Dreamworks, myself included go well beyond 14px deviation… in fact we often reach values as high as 32px and possibly beyond for some unique shots! In my two examples in this post I kept it simple and only went up to 6px just to make the graphics simpler.

Depth compression increases visibly as you move your zero parallax closer and closer towards the camera, ultimately reaching a point where your entire scene flattens out. It will eventually reach the point where you may as well be filming in 2D. For example a regular head shot often has the subject placed close to camera filling most of the frame, meaning your zero parallax has more than likely been pulled forward too. If I were to examine the background of this shot it would more than likely appear incredibly flat.

So, as I move the zero parallax closer to camera the more the background will flatten out. This occurs because you slowly move all the usable depth pixels forward leaving possibly 1px to capture a few hundred meters in ‘virtual’ or 3D depth. This, like a low resolution camera, is simply not enough resolution because all that depth is then captured in barely visible sub-pixels!

Depth compression is good & a bad thing. Its a fact of reality and thus if your shots are setup carefully they can feel very natural and just like real life…. but often we need to trick the system, fake the depth just to suit the need of the shot or to enhance the depth of a shot. This is where the Multi Stereo Camera Rig comes into play which I will cover in a future post.

Note: Lensing plays an important roll in stereography too, many old school cinematographers continue to shoot using long lenses, 70mm and above, these lenses effectively flatten the image in 2D, and thus have a huge impact on stereography, resulting in ‘cardboard cut out depth’. The recommended lensing for stereography range between 20-40mm with the optimum roughly 30mm. Yes! That is a very wide angle lens but its pretty close to the true FOV of the cinema goer sitting in the middle of an average cinema.

This was recently sent around the office here at Triggerfish Animation, and I feel its totally worth sharing! I am pretty sure that after the 20min video you will be totally inspired but may have missed some of the valuable lessons pointed out! Okay maybe you won’t but the first time I watched it I did, so I thought I would write them down! Below is a complete summary of Neil’s advice.

1. When you start out you have no idea what you’re doing! This is a good thing!
2. If you have an idea of what you want to do, or what you were meant to do… Go do that!
3. When you start out you have to deal with the problems of failure. You need to be thick skinned to know that not every project will survive!
4. I hope you’ll make mistakes! If you make mistakes it means you’re out there doing something!
5. Make Good Art! Make Your Art!! Do the stuff only you can do!
6. Some secret freelancer knowledge! Deliver On Time, Good Work, Or being likable… Just pick two! The third will be forgiven!

Extra Advice & Tips

1. Steven Kings Advice – This is really Great! You should enjoy it! -> Let go, and enjoy the ride! Don’t spend to much time stressing.
2. If a problem seems to great, pretend to be someone who can do it! Mentally it helps.
3. Be wise, because the world needs more wisdom and if you cannot be wise, pretend to be someone who is wise, and just behave like they would!
4. Go! Make Mistakes! Make Good Art!!

New to videography having recently bought a Canon 600D and the Canon 50mm f1.4 USM lens this is my first finished and edited piece.

Shot & Edited during my lunch breaks, its been a few weeks in the making… so any comments, thoughts, crits are welcome for this piece, or advice for future pieces!