ARRI ALEXA Mini LF 1:1 for 2:1 Anamorphic

Kazimir Malevich, Black Square. (1915). Oil on linen.
79.5 × 79.5 cm.
Tretyakov Gallery, Moscow.


Times Square, Joseph Albers, Rothko, Hip to be Square, Instagram 

Instagram’s tyranny of the square, as Wired called it (“an endlessly frustrating creative constraint”), has not been, shall we say, a beloved creative format. Quick, how many famous square  paintings can you name? Kazimir Malevich comes to mind. He  painted “The Black Square” around 1915, described by The New Yorker as “the most frightening painting known to man.” 

Can you imagine Leonardo Da Vinci’s The Last Supper in a 1:1 aspect ratio? Apostles expunged or endless expanses of ceiling   revealed. Instead, Da Vinci composed in 2:1. So does the disciple Storaro. We’ll get to him in a minute. 

Leonardo da Vinci, The Last Supper (Il Cenacolo). 1495–1498. Oil on dry wall. 460 x 880 cm. Convent of Santa Maria delle Grazie, Milano, Italy.

ALEXA Mini LF 2.8K LF 1:1 Square 

And so, why would ARRI include a new 1:1 square sensor mode in the latest ALEXA Mini LF Software Update SUP 7.1?  

Shoot with a 2x squeeze anamorphic lens on an ALEXA Mini LF in this new 1:1 (2880 x 2880) format, and the image desqueezes horizontally in a glorious 2:1 widescreen aspect ratio.

Furthermore, this new ALEXA Mini LF 2.8K 1:1 salubrious sensor mode has an image circle of 33.60 mm. How convenient. ARRI/ZEISS Master Anamorphic and other Super35 format lenses conveniently cover this diagonal.    

The 2:1 display format has gained popularity against widely prevalent and wider 2.39:1 widescreen for a number of reasons. 

Ministry of Magic Mandates

Mandates, variously attributed to Harry Potter’s Ministry of Magic, recommend 2:1 as being eminently more fitting for televisual, wizarding and handheld devices. Perish the thought of your 2.39:1 anamorphic epic composition compromised by chopped-off edges or dreaded black bands at top and bottom.

Univisium 2:1

Back to Vittorio Storaro, ASC, AIC. Around 1998, he said, “The composition of the image at 2:1 aspect ratio is essential for me. I took the example from Leonardo da Vinci’s fresco of Santa Maria delle Grazie in Milan, The Last Supper, as the best symbol of Renaissance art with its 2:1 aspect ratio, to invent the ‘Univisium’ system.” This was still in the analog film, pre-digital era. 

Producers had to love the cost savings that 3-perf camera negative offered. ARRI offered 3-perf movements for their film cameras. Clairmont Camera and Technovision Rome modified some of their cameras. 

Producers will continue to love the savings offered by this 1:1 camera format that stretches to 2:1.

Misuse of Muggle Artefacts Office

Meanwhile, back at the Misuse of Muggle Artefacts Office, an additional “you are requested and required” mandate suggests that camera original pixel-count be at least 4K. 

And so, ARRI product managers and engineers did the math to show how their new 2.8K LF 1:1 sensor mode qualifies for anamorphic 4K origination. Not only does it dangle the possibility of Large Format 4K, but it also enables all ARRI/ZEISS Master Anamorphic 2x lenses to fill the frame, even though they were originally designed for Super35.

See ARRI Frame Line & Lens Illumination Tool.

ARRI Frame Line & Lens Illumination Tool shows 2880 x 2880 Sensor Mode with an ARRI 28mm Master Anamorphic S35 lens.


Why and How?

But why is this format called 2.8K LF 1:1 if it’s 4K we want? The Ministry of Magic 4K Mandate states, “Camera must have a true 4K UHD sensor—equal to or greater than 3840 photosites wide.” Elsewhere, it is decreed that “UHD/4K vertical resolution shall include, but is not limited to, 2160 pixels.”   

Calculators out and ready? 3840 wide x 2160 high is indeed the common 16:9 UHD specification. Multiply 3840 x 2160, and we get 8.29 Megapixels.

Now, look at the horizontal and vertical resolution of the ALEXA Mini LF’s new 2.8K LF 1:1 anamorphically squeezed recording format. It is 2880 wide x 2880 high. Multiply: 2880 x 2880 = 8.29 Megapixels. Same 8.29 Megapixels as 16:9 UHD/4K. Even the Gringotts Goblins below the Ministry of Magic might be scratching their heads and nodding in approval. 

An advantage of shooting Mini LF 2.8K 1:1 anamorphic is that smaller files are recorded. If you were to shoot ALEXA Mini LF 4.5K LF 3:2 Open Gate ARRIRAW (4448 x 3096), whether spherical or anamorphic, file size increases to 13.77 Megapixels per frame. And you wind up cropping a lot more picture area. 


Another reason to like 2.8K LF 1:1 Square is the creative gateway it offers to use S35 Anamorphic lenses for Large Format 4K.


ALEXA Mini LF SUP 7.1 Beta 

ARRI Release Notes elaborate: 

  • The latest ALEXA Mini LF SUP 7.1 Beta includes the new 2.8K LF 1:1 recording format in ARRIRAW or Apple ProRes. 
  • This format is designed for shooting with anamorphic S35 or large format 2x lenses for a target deliverable of 2:1. 
  • By using a sensor area of 2880 x 2880 photosites, a pixel count equivalent to 4K UHD is achieved, which makes this format usable for productions that require a 4K UHD resolution. 
  • This recording format is named “LF” because its height (2880) exceeds the height of an ALEXA S35 sensor (2202 photosites). 
  • For further details, read the ARRI White Paper “ALEXA LF & Anamorphic Lenses” ( This is being updated to include ALEXA Mini LF new recording formats.
  • The official release of SUP 7.1 is expected in or by September.

ARRI 2.8K LF 1:1 ARRIRAW or ProRes

MXF/ARRIRAW 2.8K LF 1:1. Maximum frame rate: 60 fps. Sensor area: 2880 x 2880, recorded file resolution: 2880 x 2880

MXF/Apple ProRes 2.8K LF 1:1. Maximum frame rate: 60 fps. Sensor photosites used: 2880 x 2880; recorded file resolution: 3072 x 3024. The recorded ProRes clip has black borders (3072 x 3024 pixels) around the picture area (2880 x 2880). These are flagged in the clip metadata and can be cropped, often automatically, in post-production.

Since one of the big advantages of this new 1:1 recording format is the ability to avoid cropping in post, I like ARRIRAW. 

SUP 7.1 Beta additional items

ALEXA Mini LF SUP 7.1 Beta includes additional updates: 

  • Lens Data Archive files for ARRI Signature Prime Lenses and Signature Zoom Lenses
  • Sync Shift via Camera Access Protocol
  • Various bug fixes and system stability improvements
  • This is a Beta version of ALEXA Mini LF SUP 7.1. It is meant to be used for testing and evaluation purposes only, not for productions.
  • ARRI does not recommend updating in the middle of a production.

Leave a Comment

1 Response:

  1. Daniel says:

    That means that to be fully compliant with Netflix’ demands, “3.8K LF 16:9 – UHD” (Sensor: 3840 x 2160, File: 3840 x 2160) is actually sufficient? Which would be great as it goes up to 60fps.

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