Anamorphic 2.39:1 for 16:9 HD

[Benjam]

Hi everybody,

I´m shooting a crime TV series in Sweden. We are planning to shoot a dreamlike flashback sequences for our main character. The director and I want to shoot these sequences with anamorphic lenses to get the look of anamorphic lenses (flares, bokeh etc). Unfortunately we need to crop the anamorphic image to 16:9 HD (1920x1080) for delivery.

The series is shoot with Alexa MINI and Alexa SXT in 3.2K ProRes 4444 QX. The delivery is 16:9 HD for TV broadcast and web stream.

For flashback sequences we have obtained the KOWA Mirrorscope T2.3-T3.4 Anamorphic lenses with a squeeze factor of 2x

My question is:

In what sensor mode should I record in camera? 16:9, 6:5, 4:3 or Open Gate?

And what’s the resolution? 3.2K or 2.8K?

Because we need to crop/fit the 2.39:1 image to an 16:9 output I need to frame for 1.78:1. Which frames lines should I use? ARRI 1.78?

What is the best way to crop the image? We don’t want black bars on the top and bottom. This means that we need to crop the image from the sides.

Thanks in advance!

Regards,

Benjam

[David Hessel]

I would shoot open gate anamorphic, you want to have as much height on the sensor and squarest shape output to maximize resolution and minimize how much cropping of the sides you will need to do yielding a much wider FOV. If you shoot 16:9 you will end up cropping away half of your horizontal resolution and end up with the same FOV as if you had just shot spherical from the begining.

[David Mullen ASC]

If you are shooting with 2X anamorphic lenses for a cropped 16:9 image, then you are effectively using .89 : 1 area of the sensor, very vertical, and doubling that (to remove the 2X squeeze) to 1.78 : 1. So there isn't much reason to use anything other than the 6:5 mode, which records close to max height of the 4:3 sensor but not width, unlike Open Gate (Open Gate is only slightly taller). See:

 

http://www.arri.com/news/news/alexa-mini-sup-40/

 

If you are finishing to HD, not UHD, there is an option called ProRes 16:9 ANA which does all of that work for you, crops 2X anamorphic to 1.78, etc.

 

ProRes 16:9 HD Ana. is for situations where the look of anamorphic lenses is desired but the end product is full 16:9 HD without letterboxing. This mode also supports recording speeds up to 120 fps.

[Benjam]

Hi!

Thanks for the advice!

Since we are going to shoot with the ALEXA Mini and we have the ALEXA Mini 4:3 License Key, hence we can shoot in the 16:9 HD Ana recording mode, we have decided to do that.

Regards,

Benjam