Anamorphic Or Spherical

After viewing the material from the 'ASA test' we decided to rate our camera at 800 ASA and if needed, push it to 1280. 

The second test was to decide if we were going to shoot Anamorphic or Spherical.

Here we had several options. 

First I will try to explain several technical things associated with the Alexa sensor. The sensor is exactly the same in the Alexa Plus as it is the Alexa Studio, but for this blog, I will only deal with the 16:9 Mode.

Alexa Studio/Plus + M - 

Sensor Size: 3392 x 2200 pixels

16:9 Mode

ARRIRAW: 2880 x 1620 (1.78:1) (Active Pixel Area for 2K Master) 

Frameline 1.85:1 : 2880 x 1558

Frameline Flat (2.39:1): 2880 x 1205 

Frameline Anamorphic 2x: 1926 x 1620 

Frameline Anamorphic 1.3x: 2880 x 1567

see below:

So, in an attempt to explain briefly, (bear with me).

The Alexa sensor is 2880 x 1620 ( 1.78:1 or 16:9 which is also 1.78:1 [16/9 = 1.78:1]

Full HD is 1920 x 1080 ( which is also 16:9 [1.78:1]

If shooting normally (spherical) and framing for 2.39:1, you have an image area of 2880 x 1205, with 207.5 pixels (1620-1205) above and 207.5 pixels below for reframing in post.

•Anamorphic 1.3x : uses the full width of the sensor (2880), but loses several pixels on the height (1567 instead of 1620, we lose 53 pixels) Therefore when you multiply the 1.3x (2880 x 1.3= 3744) and divide by 1567 (3744/1567= 2.39) we end up with 2.39:1 ratio.

But, once we export our material at full HD (1920 x 1080), is 1920 x 1.3 = 2496 and taking into consideration the loss of 53 pixels (which translates to 1044 instead of 1080) we then end up with a 2.39:1 ratio (2496/1044 = 2.39)

Lens: Hawk Anamorphic 1.3x 110mm, shot pretty much wide open (full frame frame grab, no cropping)

•Anamorphic 2x : 1926 x 1620

However, 477 pixels left and 477 pixels right (total 954) are not used from the sensor (2880-1926 = 954), roughly 30% less. 

So, 1926 x 2 = 3852/1620 = 2.38

And now here is the interesting fact...

At full HD (1920 x 1080), 1920 x 2 = 3840/1080, gives a ratio of 3.56:1, but with 30% less width resolution

Lens: Hawk Anamorphic 2x 110mm, shot pretty much wide open. (full frame frame grab, i.e no cropping) 

Great format, but not for this movie. Maybe for my next music video or commercial.

More info to follow..

Adrian Cranage

Blog 1: Camera Prep

I am currently in pre production on a German feature film that will begin shooting early January 2012. We are/have been testing various options, cameras, lenses and workflows that I intend to maintain a regular blog on the progress, decisions and results of these tests.

I will also be uploading various clips from the results of the tests. 

Adrian Cranage

www.cranage-dop.com

So, to begin

My initial briefing (beginning November 2011). The movie was to be an action/thriller to be shot digitally, with a hand held, realistic feel. A large majority of the film is to take place at night, both exterior and interior. 

I just finished testing the following:

Alexa Plus ASA test

Hawk Anamorphic 1.3

Spherical (Cooke S4, Master Primes, Leica C series)

But we will start slow and I will begin with a couple of images from the 'ASA test'

1. Alexa ASA test.

I went out with the Alexa and shot several tests to establish how far I could push the Alexa shooting at night.

The images were all shot on ProRes 4444, white balance was set at 3200°K, 24fps, 172.8 shutter and graded on Resolve using the ARRI laser standard LUT. No grading was performed. The images were then projected on a 10 meter screen using the Lustre system.

I tried to keep my key light at a constant stop.

As was to be expected, the results showed extremely clean images at ASA 800. The images at 1600 started to show visible signs of noise and it was deemed too much for the look of the film that we are striving for. Therefore I performed a second test, simply driving around the streets of Berlin, lighting my focus puller at various stops under my lens stop (2.5 on a 50mm S4 Cooke). I felt that the best results were ASA1280 with the light panel reading 4 stops under my lens stop. (0.5 1/2).

Click all images to get bigger versions.

The following image is the same frame but from the Log C material

The following image was shot at ASA800, WB 3400, 24fps, 172.8 shutter. Cooke S4 100mm at T2.5. It has the ARRI laser LUT applied. The background highlights are available light from the main train station in Berlin, taken at around 9pm

The following is the LogC frame from the same image as above.

The same as above, but obviously the focus is on the background

Enough for now, more tests coming (testing various colours of blood under daylight and tungsten conditions)