Friday, October 2, 2009

Sony Announces devlopment of new Single Lens 3d Camera




This looks pretty cool.

Buttery smooth 3d and frame rates up to 240 fps!  Here's the cut and paste...  or the original link.

This technology combines a newly developed optical system for single lens 3D camera which captures the left and right images simultaneously, together with existing high frame rate (HFR) recording technology to realize 240fps 3D filming. Sony will demonstrate a prototype model incorporating this technology at "CEATEC JAPAN 2009", to be held at Makuhari Messe convention center in Chiba city, Japan, from October 6th.
In existing half mirror 3D camera systems with separate lenses for the left and right eyes, the parallax range is adjustable, enabling the depth of the 3D images to be modified. However, when operating the zoom and focus functions of such systems, the sensitivity of the human eye, in particular to differences in the size and rotational movement of dual images, as well as any vertical misalignment or difference in image quality has meant that complex technology has been required to ensure that each camera lens is closely coordinated, and there are no discrepancies in the optical axis, image size, and focus. The introduction of a single lens system resolves any issues that may occur as a result of having different optical characteristics for each eye.
Optical system for single lens 3D camera
Enlarge
Optical system for single lens 3D camera
Furthermore, by using mirrors in place of shutters, incoming light can now be simultaneously separated into left and right images and recorded as it reaches the parallel light area (the area where diverging light from the point of focus on the subject matter becomes parallel) of the relay lens. The separated left and right images are then processed and recorded with the respective left and right image sensors. As there is no difference in time between when the left and right eye images are captured, it is possible for natural and smooth 3D images to be captured, even of scenes involving rapid movement. Optical tests have shown that a frame rate 240fps represents the limit of human visual perception, and beyond that it becomes difficult to detect differences in terms of blur and "jerkiness" of moving images (where images that were continuous are now seen as a series of distinct snapshots). By developing a 240fps frame rate CMOS image sensor with properties close to the human eye, which is capable of capture natural images of even fast moving subject matter, Sony has succeeded in enhancing the quality of 3D video images.

The combination of Sony's new single lens 3D system and its 240fps high frame rate technology has realized a single lens 3D camera system, based on universal properties of the human eye, which enables natural and smooth 3D images with no accommodation-vergence conflict to be recorded.
Technological Features:
1. New single lens optical system
- Captures left and right images simultaneously to deliver natural and smooth 3D images with no accommodation-vergence conflict.
- Eliminates the need for lens synchronization, ensuring easily accurate control of 3D zoom and focus functions.
- When polarized glasses are not used, viewers with still be able to see natural 2D images, as the disparity of the images for left and right eyes are within the range that human eyes can recognize as a blur.
2. 240fps image capture to realize high quality motion images
- Realizes high quality capture of 3D content including fast-moving subject matter such as sports.
Source: Sony

Wednesday, September 23, 2009

HDR Aquisition - Gear

First before we get into gear, we need to decide how you want to take your panoramic HDRs.  You can shoot an panoramic HDR with just about any lens.  It just depends on how much time you have to devote to shooting your complete data set.

Generally the longer the lens the more angles you'll need to take a complete panorama.  And that will increase your final overall compiled image resolution.  The wider the lens the fewer angles you need to take for a complete set but then you will have lower resolution compared to shooting with a longer lens.  Final resolution also depends on your camera's Megapixel size.

There are lots of different types of setups for shooting HDR panoramic environments.  Below is my current setup, and I will also go over some of the alternative gear available.

Since we are talking about on set data acquisition my setup is geared towards speed.  Thus I am using a wide angle lens.  In addition I put a my 24-105mm lens and shoot a non spherical pano with the same system outline below.  This is good for background plates where resolution is the key.

My Gear for Shooting panoramic HDRs on Set.
I would consider this a solid DSLR HDR panoramic setup.  This setup has a full frame censor and the 8mm fisheye lens can shoot an entire panoramic environment with just 3 angles (120 degrees apart).

If you have a cropped censor you can still use the utilize this lens but you will need to shoot 4 angles (90 degrees apart).  Sigma also makes a 4.5 mm fisheye lens designed specifically for cropped sensor DSLRs.  They make a variety of mounts for this lens to fit cameras from Canon, Nikon, Pentax,  and Sony.  The 4.5 mm fisheye will allow you to shoot a full panoramic just like a Full Framed DSLR in just 3 angles.

With my current setup I can shoot a full panoramic HDR in about 2-4 minutes depending on the on set lighting conditions. 

There are few newer tools that will speed up this process.  One of them is the Promote Control System.  This device aims to increase the standard 3 images (+/- 2 EV) for Canon Cameras.  This system also works with Nikon cameras but some Nikon cameras have an advantage where their in camera auto bracketing takes up to 7-9 exposures.  The Canon 1Ds MkII/III is the only Canon camera the shoots an auto bracket sequence of more than 3 exposures.  It can shoots 7 (but who has $8k to spend on a camera!).

Check back as I will be reviewing the Promote Control system in the coming weeks.

Other Available HDR Panoramic Gear

If you have the deep pockets or your working on a big budget feature film you might want to check out some super custom imaging systems.  But if your pocket aren't overflowing with cash there is also some budget gear out there to get you started.
  • HDR-CAM
    • An all in one solution geared towards feature films.  This robust stem can be fired remotely meaning you can stick it in many places there it would be dangerous or impossible for a person to shoot an environment. (ex. on a Technocrane).  This system comes with a complete software package that will compile, log, and prep your HDR for import into Maya.  I believe this system is for rental only.
  • Spheron
    • The Spheron has been around a long time.  It's manufactured in Germany so it has to be good right?  This is a custom imaging system that shoots a full spherical HDR in one pass that has a dynamic range of 26 f-stops.  Like all systems I'm sure this one has a hefty price tag.  It also looks like Spheron has a service for capturing as well.. if you don't want to buy the system.
  • Panoscan
    • The Panoscan is another custom imaging system that has its optics designed for the camera from the ground up.  Some of this systems highlights (according to the website) a full scan takes 54 seconds.  Shoots in low light up to ISO 3200, Autowhite balance, accepts Mamiya, and Hasselblad lenses, and its unique magnetic slit cap improves image quality by blocking lens flares and reducing glare.  
    •  These guys demo their product for me a couple of year ago and it was very impressive and solidly designed.
  • Peace River
    • These guys make a ton of different products.  A standard pano head simular to the nodal ninja and they have a super robo automated panoramic head.  I have not used it my self,  but my good friend Eric Hanson over at xRez has been using their system for years.  I might have to swing by his shop and bring some beers to get hands on review for ya guys.
  • Ipix Products for consumer and DSLR cameras
    • Ipix has been around since 1989 and was one of the first companies to start doing 360 QTVR type stuff.  They carry Peace rivers' 3Sixty pano head but also offer lens and pano head for more consumer type cameras (Nikon P6000, P5000).
  • Panosarus
    • a budget pano head.
  • Manfrotto Pano head
    • One of the only "Big" camera accessory manufactures to get into the panohead business.  It is a solid head and does the job, but I cannot recommend it because of the complexety of its setup.  A previous company had one of these and basically it's great once it's setup and configured.. but I hope you have a good memory and some time if it needs to be assembled.
Lets not forget about tripods.  They are very important piece of the puzzle.  You don't need a crazy carbon fiber rig but if you got the cash spend some money on with with a self leveling ball head incorporated into the tripod like many of the Gitzos.

And lastly don't for get a good carrying cases and travel protection.  I love camera bags, but I have a lot of them.   But the one I use most is my Kata Rucksack.  I can jam my Camera, 8mm, 24-105mm, 16-35mm, my speedlight, battery charger, cleaning supplies, many cords and cables and I don't feel like I'm a hunch back with a big sign saying "MUG ME" i have lots of camera gear.

That's if for now... Next time we tackle the setup!  We'll configure out panohead, learn how to find the nodal point of any lens, and setup our camera.

Tuesday, September 22, 2009

HDR Aquisition - Introduction

Last week I went to a VES event on HDR usage in visual effects. After talking with a friend I realized that I have not written much of anything on HDR acquisition.

Most VFX Supervisors and artists now about HDRs. But they might not know how to capture and compile one. Lucky for us the tools have gotten much better in both areas!

Getting a good set of usable HDRs takes a bit of practice, familiarity with some basic photography rules, the right gear, and good communication with the First A.D. on set. Typically in pre-pro they're like yeah just let me know and we'll get you in there. But the reality is the second the "VFX Guy" drops his tripod on set to start taking HDRs the First A.D. is already yelling to "CLEAR SET!".

That's when practice and having the right tools on set pays off. And taking a fast and usable HDR data set will make your life a lot easier when you get back to the office.

I'm going to assume that we all know what HDRs are and how we use them in post production. But if you need a bit of a primer check out these links.
To make this a bit more digestible I'm going to break the whole thing down into separate entries.
  1. Gear - what kind of gear do you need to take HDRs.
  2. Setup - how to setup and and be "Johnny on the spot" on Set.
  3. HDR image capture - the process of actually taking the pictures.
  4. Stitching the HDRs together.
  5. Processing the HDRs and getting them into your software of choice.
The process is generally the same but there are many variations largely depending on what equipment you have. I'm going to break down my process using my gear but the general theory applies across many different gear sets.

Feel free to hit me up with any questions along the way and I'll do my best to answer them!

Tuesday, June 30, 2009

Cross Polarization Photography and Skin Texures

Hello Everyone,

Here is a good trick for capturing only the diffuse component of a person for the basis for diffuse texture maps in a sub surface scattering shading model.

Bascially what you need to do is filter both your lens and your light source. In this case I am filtering a pair for canon 430 EX speedlights with linear polarizing film. The speedlights are mounted on a custom bracket. The purpose of the bracket is to align speedlights with the camera lens in order to evenly light our subject. (me)

First lets look at the results.


(note: the small amount of reflection/specular light on the right hand image is the uncorrected lights in my kitchen. Ideally you would take your photo in a more controlled setting. Also for this example I did not have 2 flash units available so I just used one directly on the hot shoe of the camera)

Why does it work?
Well when I first learned this trick back in the day.. I was just told "it works". But I wanted to know why so I did some digging. Here is what I've found.

I am paraphrasing The Handbook of Cosmetic Science and Technology, Third Edition. Cross polarization photography lets you differentiate between regular glare and back scattered light. The back scattered light is the complextion within the skin.

Both the camera lens and the flash have a filter placed in front of them. When the orientation of the filters are perpendicular (cross polarization) the regular glare is blocked and only the back scattered light is captured.


But when the filters are parallel only the reflected polarized light passes though the filter to be captured by the camera.

What do I need to take photos like this?

The Basics
More Advanced Setup
  • Camera
  • Circular Polarizer for your camera
  • External Flash units (I used 2)
  • Linear Polarizing Film (to filter your flash)
  • Flash diffusers (make sure the one you buy fits your flash)
  • Flash bracket (My good friend and boss Les Ekker helped me make a nifty bracket)
  • An external hot shoe extensions
  • An adapter to connect more than one flash to your PC sync port
  • Extra tripod mounting plate
  • some standard "quarter/20" screws (1/4 inch screws with a 20 degree pitch threads). This will fit a standard camera mounting hole.

The Flash Bracket


Les had some extra 1/4 aluminum stock laying around so after some carefull planning we drilled a bunch of through holes. 2 hole for the hot shoe adapters. 1 hold for the camera, and the last through hole we threaded and attached a standard tripod mounting plate.

After we did all that... we threw the thing in a vice and gave it a good twist. This was to align the flashes as best as possible with the front of the lens.

presto chango.... hand dual flash bracket! (when I say we...I mean Les, he did most of the work as I drank a beer in his shop.)

Making the flash filter



The flash filter was simple to make. I ordered a sheet of the polarizing film and simply used a sharp exacto knife to cut out a shape that matched the end of the diffuser. We simply taped the film to the end of the diffuser with some common "silver" tape that you can find at the hardware store. I think its generally used to repair dryer hoses. The silver tape will help contain any light leaks from the flash and focus as much light out through the filter.


Shooting Conditions

When shooting you want to control as much as the light as possible and have little or no reflective/specular light sources. (light fixtures, computer monitors, windows etc...)

make sure to focus and have fun.


Now what do I do with these...

Once you've taken a set of photos in each position (perpendicular and parallel) you can do some fancy photoshop action by either inverting or using difference matting techinques to derive a specular only map. These 2 images will take you a long way.


But wait there's more....

This technique works on all kinds of stuff. I've used it to shoot rubber tires, plants, leather and a bunch of other stuff...


here is a link to a page that I came across in my researching for this project.... just wanted to give some credit to naturescapes.com

Here is a flickr gallery that has more pictures of the rig.
enjoy

Andy

Wednesday, February 11, 2009

The Integration Company

I wanted to give a quick shout out to Tim Conway and Del DePierro over at The Integration Company. These guys are top notch on set Supervisors and Integration specialists. They offer a wide variety of services ranging from on set supervision, data acquisition, HDRI, camera tracking, scene layout and more. Swing by their site to see some of the great work they've done.

If your looking to outsource some integration work, I wouldn't hesitate to use these guys. In fact pick up the phone and call them now!

I'll be sitting down with these guys in the coming weeks to squeeze some good tips from them, and it would be "terrible" if this all happend over a pint of beer or two!

until then!

Andy

Wednesday, February 4, 2009

HD Lens to 35 mm equivalents

While on a shoot with an HD camera you will almost definetly here the question

"What is the 35mm equivalent of this lens?" Well you can do some fancy math... or use a handy cheat sheet from Panavision. Of course it's only accurate for Panavision lens but it give you a pretty good idea of what your seeing in a 35mm equivalent across the board.


You can down load the full PDF and a simular one here from Panavision's website. This was another gem from Les. He has a photo copy of a photo copy of this document and I did some digging with the help of Johnny B at work and found this on the web.

Enjoy!

The perfect tracking marker

Hey everyone,

Are you ever stuck with the problem of choosing the right tracker size for the shot? This tiny formula is useful since it works for every scenario. It takes into account the different parameters that can effect the camera angle and the number of pixels in the image.

This tracking marker tip comes from Francois Lord. Francois has been tracking since the 3d equalizer days and has spent a lot of time on set. He has devised a very creative and exact solution on how to calculate the perfect tracking marker size. This formula has been refined over the years by Francois and he was kind enough to share it with us. And now here is ....

The Flord Formula


Where :
T = Tracker size (in same units as D)
P = Prefered tracker size on screen (in pixels) between 5 and 10 pixels depending on the software you will use for tracking
B = Filmback (in millimeters) see table below for reference
D = Distance from camera (in units of your choice)
F = Focal length (in millimeters)
R = Horizontal Resolution (in pixels)

So... If you are shooting a scene with a 35mm camera and a 18mm lens, transferred to NTSC, and the background is at 3 meters from the camera... you can use the following formula...



...to find out that you need to put trackers that are 5 centimeters in diameter on the background to have them appear as 8 pixels big on screen.

Here is a list of different filmbacks that are often used in production. Please let me know if any of this information is inaccurate and I will update it.

Format Name
x size (mm)
y size (mm)
35mm (Super 35) - Full Aperture 24.89
18.67
35mm (Super 35) - 3-Perf
24.89
14.20
35mm (Super 35) - Transfered to HDTV
24.89
14.00
35mm - Academy
21.95
16.00
35mm - Slide
36.00
24.00
16mm - Standard
10.26
7.49
16mm - Super 16
12.52
7.42
70mm - IMAX
70.39
52.62
Video HDTV - 2/3" 16:9 sensor
9.59
5.39
Video HDTV - 1/3" 16:9 sensor
5.23*
2.94*
Video NTSC - 1/2" 4:3 sensor
6.40
4.80
Video NTSC - 1/3" 4:3 sensor
4.80
3.60
Video NTSC - 2/3" 4:3 sensor
8.80
6.60

* I'm not 100% sure about this one yet.

Again, thanks to the Francois. And if anyone is savvy enough... I smell a really good iphone app or java application.

until next time.

Andy

Monday, February 2, 2009

Good Iphone apps for VFX from VFXHack.com

In my daily search for the end of the internet I swung by one of my favorite sites to see what is new. And vfxhack.com had a great little blog entry about good iPhone apps for on set VFX guys.

They are Clinometer, HDRhelper, Jott, Dropbox, and Google apps. To see how he uses them... cruz on by www.vfxhack.com.

Sunday, January 18, 2009

Simple Survey: Suunto Tandem Inclinometer

Once piece of equipment that isn't in my bag yet but is very handy is the Suunto Tandem compass & inclinometer.

This simple piece of equipment can do many things. It can help you figure out where the sun is going to be at a certain time of day. It is very handy when setting up for golden hour shoots. It can help you figure out how many degrees a camera pans. It can also help you align your directTV satellite dish!

The tip I'm going to talk about today is how to use an inclinometer to do some simple and quick outdoor set surveys. All you need is the inclinometer/compass, a laser tape measure, and some simple math.

This piece of equipment is sometimes referred to as a "sighting" compass because the compass/inclinometer is read by looking through an eyepiece on the side of the unit. There are two eye pieces and two floating dials on the device. For purposes of this tip we're just using the top dial, the inclinometer.

Hold the inclinometer vertically so that you're looking through the eyepiece with one eye. It takes some getting used to reading because you actually read the inclinometer's scale with one eye, and sight your target with the other eye. If you're using this for the first time it may be simpler to close one eye first, focus on the scale, then open your other eye and sight your target. You need to relax your gaze so that you are looking at both the scale and your target that you want to measure. This is the most difficult to master when using this device.

Hold the scale to your dominate eye and sight with the other eye. Then simply tilt your head up and down and the scale will tell you what degree of incline you are sighting.

Ok, now that we know how to use it, let's measure something. In the above image I want to measure/survey the wall height.

In this example A, D, M, N are values that you can easily measure. B, C are difficult to measure. The Wall Height = B (calculated side of our triangle) + D (distance of our eyesight from the ground).

The first measurement we will take is "M". "M" is the angle from your eye to the top of the building. A good way not to use a lot of math is to use the 45/45/90 deg triangle method. Sight the top of your target and move closer or further away until the angle of sight is 45 degrees. Using simple math principles we know that that "N" is also 45 degrees.

From this position sight down to zero degrees. This is the base of our right angle triangle. Now we calculate distance A by using our handy Hilti laser tape range finder, measure the distance from where you are standing to the "Zero Degree incline" line you just measured.

A = 25'5". Because in a 45/45/90 degree triangle A = B. We also know that B = 25'5"

Now we measure the D. D is how far your eye line is from the ground. In this case D = 5'4".

B + D = Wall Height
25'5" + 5'4" = 29'9"

There you have it. Our wall is approximately 29'9". Now of course this isn't EXACT but its close enough to help us set a scene scale or create tracking geometry for this building.

If you can't for use the 45/45/90 degree triangle method you can still derive the distance of B but you'll need to do a bit more math. I'm not a mathemagician so I use cheat sheets. A buddy of mine (Mike Romey) showed me these Quick study laminated charts. These reference charts are another great addition to the tracking kit.

I'd like to thank Les Ekker for showing me this tip. Les is a VFX Supervisor at Zoic Studios and is an encyclopedia of VFX knowledge. I'm sure we'll see many more tips from Les.

And thanks to Max for helping me out and posing for the reference pictures.

If you have any tips that you would like to share please email me at vfxtips(at)wilkoff(dot)net.