Alexa High Speed Upgrade

Alexa High Speed Upgrade

I had a chance to check out the newest Alexa features last weekend and they're super cool. I also checked out the upcoming Alexa Studio which allows for an optical viewfinder as well as the EVF, true digital anamorphic, and includes the new High Speed 120fps frame rate option. As far as I could tell, the Studio is about the same size as the Alexa Plus. I was expecting it to be quite a bit bigger than the other cameras so this is good news. 

It's no Phantom but it's certainly a big improvement. 

The Alexa High Speed upgrade is a paid license but I don't recall the price off the top of my head. The new Sony 64GB SxS Pro cards are requisite to doing both 120fps shots at ProRes 422HQ and 60fps shots at ProRes 4444. Note the cheaper SBS version of SxS card with the orange plastic band doesn't have sufficient write speeds for use with the Alexa. 

The high speed option has to be turned on via the "Recording" menu in the camera and it takes about 40 seconds to load. 

up to 120fps @ProRes HQ to SxS cards

Note that when the High Speed option is turned on, you get a "HS" next to your frame rate on the home screen. While in HS mode, you cannot turn on the 4444 codec. 

up to 60 fps @ ProRes 4444 to SxS cards as well

For the work I do - commercials and episodic - it seems like it's going to be Alexa for some time to come. Now with the Studio option, 120fps, and more cost effective ways of recording Arri Raw, it's even more versatile and well suited for the rigors of production. ProRes 4444 to SxS cards has proven to be a great format for broadcast destined projects. It's definitely not the most robust or high quality image you can get out of the Alexa but as has been proven time again, good enough for TV. Not only that but if anyone saw Nicolas Winding Refn's film Drive, this was shot dual link 1080p 444 to HDCamSR at Standard Quality 440mbps. I've seen it projected digitally several times and I think it's some of the best digital cinema I've seen yet. Incredible resolution, dynamic range, and virtually noiseless images. It's stunning work and a kick ass movie to boot. The soundtrack is amazing as well. 

120 fps on Alexa

120 fps on Alexa

120 fps to ProRes HQ recorded right to on-board SxS media. There is no sensor windowing to achieve this higher frame rate so no change in Depth of Field, Field of View, or Dynamic Range. I was under the impression that this functionality would be arriving very soon but no time frame has been set other than "later this year".

The Side Effects of High ISO Videography

The Side Effects of High ISO Videography

I'm often still a little shocked at just how light sensitive the Alexa really is. When I'm at my cart evaluating images shot with a fast lens at ISO 800, they are often far brighter and better defined than what you see on-set with your own eyes. When the gaffer is wishing he had 40 watt open face lights, you know you're in a brave new world. Working at such a low foot-candle becomes challenging in new ways and as I've discovered, there are a few fascinating side effects. 

Red Eyes in Motion Picture - an effect that used to be very difficult to achieve on film is now far easier. For better or for worse. 

When your key light source is a scant 3 foot-candles, the human eye naturally dilates considerably to accommodate such low light. When you have a source close to the lens such as a ring light and your subject's pupils are in this state, you can very easily end up with eyes that look like something like this (model on the right) -

Alexa v3 @ ISO800, Cooke S5 @ T1.4, 2.75 Foot-candles

As we associate red eyes with cheap stills photography, seeing this effect in motion pictures is truly strange. The only work around is work at a higher foot-candle so the talent's eyes can adjust or to keep all your sources away from the lens. 

Very interesting stuff.

Here's something else I've noticed. When you're working low light like this, the DP often wants to put ND gel on the lights themselves so to avoid dimming and color temperature shift. When you have 2 or 3 layers of this stuff on any head - tungstens especially, you will invariably need some minus green gel as well as lots of ND will usually pass more green light than red and blue. Finding the green in the scene becomes a new challenge. One more thing to keep that critical eye on the look out for. 

On an Alexa related note - my fav on the fly color correction app, LinkColor, just got an update and can now import Iridas cubes from the Arri LUT Generator. I've been using Arri's basic 3D Log to 709 as my starting point as the contrast in this LUT matches what the DP is seeing on the Mon Out on the camera. This has worked out great because if he/she likes the contrast they see on their on-board monitor, you can now very easily match it on your correction with this LUT and then tweak from there. It's a great way to begin your look.