First Impressions of the ARRI ALEXA LF

Getting a Closer Look at ARRI's Large-Format Camera System

Published on in Equipment / Tech Reviews

I usually like to start most of our discussions with lots of questions. But this time, I only have one question. What is the ARRI Large-Format Camera System? I had to know. Featuring a sensor slightly bigger than full frame, ALEXA LF records native 4K with ARRI’s best overall image quality. Filmmakers can explore a large-format aesthetic while retaining the sensor’s natural colorimetry, beautiful skin tones and suitability for HDR and WCG workflows. The ALEXA LF supports multiple recording formats, including efficient ProRes and uncompressed, unencrypted ARRIRAW up to 150 fps, provide total flexibility.

“The larger ALEXA LF sensor has the same optimal pixel size as other ALEXAs, resulting in a 4448 x 3096 image,” says Marc Shipman-Mueller, ARRI Product Manager for Camera Systems. “This doesn’t just add definition, it creates a whole new look—one that is truly immersive, with a three-dimensional feel. The various recording formats and sensor modes make this look available to all productions and satisfy any possible deliverable requirement.”

 Ok, where do I sign up to shoot my next project with this remarkable camera? What a big, beautiful, clean image. But before I get ahead of myself, let me share some background information that will help fill out the picture. 

Setting the Scene

Starting out, I gathered up a few cinematographer friends of mine, Sean McVeigh and Mike Davis. Both of these great guys have killer reels and a keen eye for detail. Going into our session, we weren't quite sure what to expect. We all knew of the reputation of ARRI going in, but wanted to see what the ALEXA LF was all about for ourselves.

We met up with Guenter Noesner, Senior Technical Sales Representative from ARRI in the studios at New England Institute of Technology. Guenter really put the ARRI ALEXA LF through its paces. He had a great deal of insight into the ALEXA LF and the philosophy behind the development of the ALEXA LF. After a short amount of time setting up the camera, it was time to get down to business.

The Warm Up

The ARRI ALEXA LF is built in a very solid fashion — like all of the other cameras in the ARRI family. The ALEXA LF had a very familiar set up and design that makes it easier to operate. It is a lot of camera! Everyone in the studio that day smiled and agreed that going handheld for any amount of time was probably not going to happen, at least for that session. You could do it, but for how long is anyone’s guess. But no worries, we had a nicely weighted tripod and it handled everything just fine.  

All the controls were on the side away from the operator, which makes it easy to adjust any settings. The recording setup and external menu controls are spot on. Currently, the ALEXA LF camera protocols indicate running Software Update Packet SUP LF 2.0 and should only be used with 1TB or 2TB SXR Capture Drives. There will be other recording options down the road, but the unit we used had the larger recording drives. But after that, all the normal things one would expect. That is a good thing for everyone on the shoot. No surprises which is always great.

We were on A/C because we were in a fixed studio location. If you do need to go with battery power the ALEXA LF does require a different type of battery due to a higher power consumption as listed on the ARRI website. But like anything else, if you were going into a big shoot most people would have that sorted out way in advance. 

Sensor Versatility Is the Key

A couple of things became very apparent to the group as Guenter went through the ALEXA LF. Mike (the professor) made a very astute observation early on. The group was talking about the sensor and the ability for the operator to have a fair amount of flexibility when choosing what you wanted to do with the sensor. Guenter pointed out how one can choose the sensor size to fit the aesthetics of what you were trying to accomplish. 

Being new to having these great options the group asked:

What are ALEXA LF sensor modes and why does it matter?

I know some of you know this already but some might not. A sensor mode is an operating mode where a certain area of the sensor is being read out. Sensor modes influence what lenses cover the recorded area, if surround view is available, the maximum frame rate, and the recording data rate.

Images from ALEXA LF's large format sensor can be recorded in one of three sensor modes: LF Open Gate, LF 16:9, and LF 2.39:1. 


LF Open Gate

LF Open Gate provides the maximum sensor area (36.70 mm x 25.54 mm) and maximum resolution (4448 x 3096 photosites) for maximum flexibility in post. This sensor mode is covered by full frame lenses, the ARRI Master Macro 100 and by some Super 35 lenses with expanders. The maximum frame rate is 90 fps. Since the entire sensor is recorded, surround view is not available and this mode has the highest data rate.

LF 16:9

The LF 16:9 sensor mode covers the smallest area (31.68 mm x 17.82 mm) that still meets 4K deliverable standards with its 3840 x 2160 photo sites. Full frame lenses cover this, of course, but the use of Super 35 lenses is also possible, maximizing lens options. LF 16:9 has surround view available, indicated by the dotted yellow line in the drawing below. The maximum frame rate is 90 fps. 
Note: The LF 16:9 sensor mode has exactly the same height (2160 photo sites) as the 6:5 anamorphic sensor mode on Super 35 ALEXAs (2578 x 2160), so this mode is great for use with Super 35 anamorphic lenses. Simply crop the sides in post.

LF 2.39:1

The LF 2.39:1 sensor mode combines a cinematic widescreen image

(36.70 mm x 15.31 mm - 4448 x 1856) with high frame rates of up to 150 fps for slow motion. This sensor mode has the lowest data rate. In order to maximize frame rate, no surround view is available. 
Note: both ALEXA Super 35 3.2K (3200 x 1800) and ALEXA Super 35 2.8K (2880 x 1620) fit within the image area recorded in this sensor mode.

LPL Lens Mount

A crucial element of this new system is the LPL lens mount, optimized for large-format sensors. A wider diameter and shorter flange focal depth allows the ARRI Signature Prime lenses and all future large-format optics to be small and lightweight, with a fast T-stop and pleasing bokeh—a combination of features that would not be possible within the confines of the PL lens mount. The LPL mount will also be available for other ARRI cameras such as the ALEXA Mini, and is being licensed to third-party lens and camera manufacturers.

The Signature Prime Lenses are Swoon-worthy

I have a new lens crush. Wow. When Guenter broke out the Signature Primes we were all just taken aback. Guenter used this time to show us the incredibly shallow depth of field. Accompanying the ALEXA LF camera are 16 large-format ARRI Signature Prime lenses, ranging from 12 mm to 280 mm and fitted with the ARRI LPL mount. The Signature Primes were designed to render organic, engaging images, gently softening and texturizing the large format with natural skin tones and fantastic bokeh. A fast T-stop of T1.8 facilitates shallow depth of field and the smooth focus fall-off gives subjects a heightened presence in the frame. 
The ARRI Signature Prime range is also the first cine lens series to feature machined magnesium lens barrels, making the optics lightweight. They are also the first to incorporate ARRI’s next-generation LDS-2 Lens Data System, with high data rates and absolute encoders for fast initializing.

After a lot of fun and spirited discussion, we all came to the conclusion that ARRI really hit the mark with the ALEXA LF. Bottom line: we all want to shoot with it! Guenter pointed out quite correctly that one of ARRI's strengths was their color science that stood out. The science is great but we also agreed that making beautiful pictures was the ultimate goal.

The question you have to ask is are you ready to take advantage of all that camera? New shooters might almost be overwhelmed. I know I would want a good chunk of time to shoot test footage and see where the ALEXA LF could take my audience. I'm voting that it would be awesome results. Also built in was the fact that the ALEXA LF is a Netflix approved camera and that you can actually buy it not only rent it. Between the camera, the new lens and the LPL adapter ARRI is going to be quite busy getting these out to customers in the months ahead.

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About the Author

Mark Foley
Mark Foley
Mark J. Foley, MBA BA is an award-winning producer and director and the Technology Editor for He is on a mission to provide the best in new equipment reviews, along with exclusive analysis and interviews with the best, the brightest and most creative minds in the entertainment and production business. Have a suggestion for a review? Email Mark at

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