Why the focus on EX cameras?

In the past, I’ve used either a Panasonic or Sony CineAlta full size camera for HD productions.

In 2008, I began researching gear for a documentary project.  I was considering the Red, but after viewing the camera at NAB... I realized it was too high maintenance for most documentaries and was better suited for productions with larger crews... feature films, commercials and music videos.

That year Sony had just released the CineAlta EX series.  In the beginning, I was skeptical of these smaller cameras, but I learned to like the format, because of the quality of it's image, size, and ability to shoot in very low light. 

EX cameras are well suited for documentaries.  In 2008, I used an EX1 on shoots in Iceland, UK, India, Pakistan, Guinea, Australia and Canada.  The camera worked flawlessly in the rain, heat and cold.

While on location, I stored the HD video files on 3 portable hard drives.  I kept one, the other crew member kept the 2nd and I shipped the 3rd drive back to the editor.  Often, by the time I’d returned home, part of the film had already been cut.

In 2009, the EX3 became 'la camera du jour' for many independent filmmakers and was accepted by most broadcasters as an acquisition format.   I’ve used the camera on commercials, TV shows, corporate videos and a 90 minute feature doc which will screen in 35mm.

In 2010, I plan on buying more attachments for the EX3, including an adapter which will allow me to mount Nikon lenses.  I also plan on getting a Canon EOS 5D or 7D  to use as a 2nd video camera.

The Global Shutter / Rolling Shutter Debate

Posted By Mitch Gross On April 15, 2009 @ 1:42 pm In Phantom High-Speed, RED One, Sony / XDCAM / SxS

There’s a lot of misinformation out there about rolling shutters on electronic cameras and how they do or do not affect the image. The popularity of the Sony PMW-EX1 and EX3 cameras has really stepped up this debate. But what does it actually mean? In brief, a Global Shutter captures all of the information from every photosite on a chip all at once. A Rolling Shutter reads off the photosites line by line. But that’s just the beginning. Let me try to clear up some misnomers and misconceptions.

WHY ONE VERSUS THE OTHER?

First off, CMOS does not necessarily mean rolling shutter and CCD does not necessarily mean global shutter. Predominantly that is the case, but it is not an absolute. There are CCD chips with rolling shutter and CMOS chips with global shutters. Also, the notion of rolling shutter = bad / global shutter = good is not particularly true either. A rolling shutter can have a more organic, more — wait for it — FILMIC look. Note I said ‘can’ as there are no absolutes in this world. A rolling shutter can also dramatically increase the fill factor of a photosite, making for greater sensitivity and a higher signal to noise ratio. All of the technical, industrial Phantom cameras from Vision Research have global shutters, as they have a specific technical need to capture an image all at once for analysis purposes. But when they decided to make some Digital Cinema cameras, the Phantom HD and Phantom 65 were both designed with rolling shutters instead.

And all rolling shutters are not alike. For instance, because of the high speed nature of the Phantom cameras, the read/write time of the rolling shutter of a Phantom HD is just one millisecond. That can be long enough not to sync with a fast strobe or lightening bolt, but you’d be hard-pressed to see any “wobblies” in a whip pan or helicopter shot.

A rolling shutter does not scan one line, then another and then another. It is more of a cascading effect. For example, when the first line of the sensor reads around 5% across, the next line starts and reads 5%, and then the third line starts and so on. That’s why it can tilt an image with movement in one direction and break it apart with movement in the other.

SO ANYWAY, HOW DO THE EX1 & EX3 DO?

Pretty good in my book. Yes, if I shake the camera in crazy ways I can definitely see the effect. But in general there is no issue even in handheld work. It is fine for car shots, and in fact Abel rented a pile of EX3 cameras to Ugly Betty for a couple of days of car rig work. They pointed them out in every possible direction on a vehicle-mounted stabilizer head, locked them in sync and drove all over New York. They used the footage for background plates in all their driving process shots.

I’ve seen some examples of rolling shutter artifacts that would not be appropriate for professional image capture. But that is certainly not the case with the EX3.

DOES A ROLLING SHUTTER CAUSE LIGHTS TO FLICKER?

Don’t get confused by the function of a rolling shutter. Think of it like a mechanical film shutter. There is only a small fraction of the time that it is physically covering up or uncovering the imager (the read/write time). The vast majority of the time the imager is either exposed to light or is not collecting photons. An LED light, some small on camera lights, tungsten lights, and even HMI lights use pulse-modulation to control exposure. This is because other forms of dimming, such as lower voltage, can cause color shift. Different lights do it differently and different camera sensors are affected by it differently.

As a test, I pointed an EX1 camera at a variety of LED lights (LitePanel 1×1, Rosco LitePad, LEDZ, Switronix TorchLED) here in our Sales showroom.  I ran the camera at different frame rates and with different shutter speeds.  I randomly adjusted the lights throughout their range.  I was unable to create any flicker.  I WAS able to create flicker with a Phantom camera shooting at very high framerate, but this was true for either Global or Rolling Shutter cameras.  So does a rolling shutter cause lights to flicker?  Nope, no more than any other form of shutter

Article printed from CineTechnica: http://blog.abelcine.com

URL to article: http://blog.abelcine.com/2009/04/15/the-difference-between-a-global-shutter-and-a-rolling-shutter/

What is CineAlta?

CineAlta is a brand name used by Sony to describe various products involved in content creation, production and exhibition process within digital cinema workflow. Products branded by CineAlta include cameras, camcorders, recorders, cinema servers and projectors.

Format

CineAlta cameras record onto HDCAM tapes, XDCAM Professional Discs or SxS flash memory cards. They have the ability to shoot at various frame rates including 24fps and have a resolution of up to 1920 by 1080 pixels.

History

In 2000 George Lucas announced that Episode II of the Star Wars Prequel Trilogy would be the first major motion picture to be shot 100% digitally.  Sony and Panavision had teamed up to develop the High Definition 24P camera that Lucas would use to accomplish this and thus the first CineAlta camera was born.

The F35 is the latest CineAlta camera, with a single 35mm CCD image sensor. It has been designed to compete with the Arri D-20 and the Panavision Genesis, which also use 35mm image sensors.

XDCAM EX

The EX cameras uses the newly developed SxS PRO memory card, which is based on the ExpressCard industry standard, as its recording media.

Both the PMW-EX1 and PMW-EX3  use three 1/2-inch CMOS sensors, 1920 x 1080 and 1280 x 720 HD recording capability.

The cameras are switchable between 1080P, 1080i and 720P with a multiple frame recording capability such as 59.94i, 50i, 29.97P, 25P and native 23.98P.

They offer a "Slow & Quick Motion" capability, which is also commonly known as "over-cranking" and "under-cranking", allowing users to create unique looks or slow and fast motion effects.

Source: Wikipedia

Here are some excerpts from an interesting article written by DOP Robert Primes. 

MUSINGS ON EXES by Robert Primes, ASC

The Sony PME-EX3 Camcorder.

by Robert Primes, ASC

During the past few months I’ve had the pleasure of demonstrating or speaking about 3 different cameras from 3 different companies, Canon’s 5D Mark II, Panasonic’s Varicam 3700 and Sony’s EX-1/EX-3. I happen to love all three cameras so I felt no conflict of interest. But I’m impressed that all three of these major companies trusted me to present their cameras and allowed me to remain an objective voice speaking from my real world experience.

I believe this ecumenical spirit comes from the many years competing vendors of cinematography products shared a stage speaking to the American Society of Cinematographers as educators rather than rivals. There is something noble about the way competing cinematographers share their secrets and wish each other success. Miraculously, the higher purpose of advancing the art form seems to supersede individual ambition. The manufacturers seem to have caught the same bug. Hallelujah! But I’ve been asked to write this article about the EXes. So here goes.

Sony’s EX-1 and EX-3 are cameras that I might never have considered. They’re small and at first glance look like fancy consumer cameras. Most of my life’s work has been shot in 35mm and when the EX-1 came out I had recently shot a movie with the excellent Sony F-23, a camera system that cost over a quarter million dollars.....

....no one there knew the ISO of the camera or how it was set up. We just saw those gorgeous images and totally flipped out. This wasn’t supposed to happen in this price range!

... another new widget that extends the EX’s power even farther is the brilliant Jon Thorn designed AJA Ki-Pro box...  instead of being limited to the EX’s excellent looking 8 bit 4:2:0 long GOP compression, you now have Apple’s far better 10 bit 4:2:2 compression, an improvement you might not notice on the tube but you’ll almost certainly be affected by on the silver screen.

The complete article can found here:

http://www.highdef.com/index.php/2009/11/musings-on-exes/