Tuesday night we hosted the guys from ARRI to show off their Alexa digital cinema camera to our friends and clients.  Here's a recap of the evening, in two parts.  Next week we'll talk about some of the technical details about working with the Alexa.  

First off, a special thanks to Assimilate, Inc and Lucas Wilson for getting this event going for us.  Second, we're indebted to ARRI, including Stephan Ukas Bradley and Michael Bravin who came early Tuesday afternoon to hang out with us, let us take the Alexa out for a spin, and make sure that the images plug right into our pipeline.

We wanted to show the speed that you can work with the Alexa and their DTE "Direct to Edit" technology, so we asked Stephan to show up around 2:30 PM to help us shoot some test footage that would be shown at the 7 PM event.  Within 15 minutes we were up and walking around our building with the Alexa, shooting directly to Quicktime ProRes 4444 in LogC to the on-board SxS solid state media.  We ran one shot, pulled the SxS out and brought the data over to our color system PC.

Leandro Marini (Leo), lead colorist and founder of Local Hero, graded the shot within seconds while we watched the image in our DI theater, jaws agape.  Our test subject (and DI producer) Rain was standing in the shade, with the blasting 100 degree sunlight just behind her.  Not only could we see every detail in the blacks of Rain's hair, but not one piece of the background or sky was blown out to pure white.  The Alexa has a unique approach to exposure, so they're able to achieve some incredible HDR results.  They claim 13.5 stops of dynamic range, however some tests like an excellent one by Art Adams have shown as much as 15 stops.  

Leandro Marini shoots test shots of Rain Valdez using the ARRI Alexa

Without getting too technical, LogC is ARRI's description of the way that the image is encoded across the ProRes bit space.  They use a film-like log curve in order to save as much detail in the blacks and highlights as it can, rather than using a standard HD Rec 709 gamma curve.  When you look at the image without color correction, everything looks flat, grey and desaturated.  But once you get into the image you find you have tons of latitude to take the image wherever you'd like.  More about that later.

Confident in our workflow, we took the camera down to Ocean Park (we're in Santa Monica), and rolled a few more test shots.  We shot Rain without any reflectors, lights, or bounce boards.  The only thing we used was a couple ND filters to knock down the light input for the camera's 800 ISO rating.  Most digital cameras couldn't even handle the contrast of the sunlight on her face, let alone keep the details and exposure in the sky and ocean.  Sometimes Rain's face would totally be in shadow, yet would still look great back in the theater.

Soon the wine and cheese was out in force (we had a wonderful spread by Ximena and Jillian's excellent catering service).  As people started rolling in, we had our test footage, as well as ARRI's other Alexa demos running in both the DI theater and our broadcast color room.  We pushed and pulled the images around, and a couple people braved the chair themselves to see what was there.  It was a treat to have the ARRI guys answering everyone's questions directly.

Stephan Ukas Bradley of ARRI answers questions

As if shooting a couple hours before the event wasn't complicated enough, we had to go one step further.  When the sun was fully down, we grabbed the Alexa once again and stepped out to the street.  Olympic Blvd was busy with cars, and the front of our building has no significant lighting.  To show off Alexa's astounding sensitivity, we rolled off a couple more shots.  One used only a street light, the other had nothing but a tiny bit of building light casting a greenish tone onto Rain.  Both of these shots were also incredibly workable once we put them in Scratch.  It was good to see both extremes at once-- bright direct sunlight and darkness using only available sources on the street.  The Alexa can literally see brighter images than the naked eye.

Local Hero's broadcast color suite

Later in the evening we sat down for a more formal introduction to the Alexa, with Stephan leading us through the overview.  Then Leo turned down the lights and brought up the footage we shot.  Everyone could instantly see how fast you can get a pleasing image from the 12-bit LogC ProRes 444, and then the directions that you can take the color from there-- with no hint of banding or compression up on the big screen.  The night shots were incredibly clean, even the one we rated at ISO 1600 with virtually no light on Rain's face.

Local Hero's DI Theater

Assimilate Scratch will be one of the systems leading the charge into the ARRIRAW format, as soon as it is released in November.  With ARRIRAW you get uncompressed 3K sensor data, with none of your ISO or color decisions baked in to the image.  The ProRes 444 is an incredibly user friendly way to go with extreme latitude and flexibility with your image.  But for even more critical situations, the ARRIRAW will offer a level of quality and flexibility even further beyond that.  Local Hero will be ready to go as soon as ARRI releases the software update.

Thanks again to everyone for coming out.  Next week look for a more detailed tech discussion, with some links to our Alexa footage, LogC images, before & after's and more.

Andrew Wahlquist