Featuring a sensor slightly larger than full frame, ALEXA LF records native 4.5K with ARRI’s best overall image quality. This allows filmmakers to explore an immersive large-format aesthetic while retaining the sensor’s natural colorimetry, pleasing skin tones and stunning capability for HDR and WCG workflows. Versatile recording formats, including efficient ProRes and uncompressed, unencrypted ARRIRAW up to 150 fps, encompass all on-set workflow requirements.
ALEXA LF has the largest sensor of any full-frame cinema camera on the market. Maintaining the ALEXA family’s optimal pixel size for best overall image quality results in a 4448 x 3096 picture, which can be recorded in full, up to 90 fps, using the LF Open Gate mode. An LF 16:9 mode maximizes lens options while meeting 4K deliverable standards, and an LF 2.39:1 mode combines a cinematic widescreen image with high frame rates up to 150 fps for sensuous slow motion. All sensor modes offer true 800 ASA sensitivity as well as reduced noise, providing the perfect canvas for modern, subtle lighting techniques.
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.
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. While the Signature Primes exemplify state-of-the-art optical precision, they have been designed to render organic, emotionally engaging images, gently softening and texturizing the large format with natural skin tones and creamy bokeh. A fast T-stop of T1.8 facilitates shallow depth of field and the smooth focus fall-off gives subjects heightened presence in the frame.
The ARRI Signature Prime range is the first cine lens series to feature machined magnesium lens barrels, making the optics incredibly lightweight and robust. 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. LDS-2 extends the possibilities of lens data and is being licensed to other lens and camera manufacturers.
Although the camera, lens mount and lenses are new, full compatibility with existing PL mount lenses and ALEXA accessories is a cornerstone of the system’s design. A PL-to-LPL adapter offers backwards compatibility with all PL mount lenses, be they Super 35 or full frame. The adapter attaches securely to the LPL lens mount without tools, allowing crews to rapidly switch between PL and LPL lenses on set. Cinematographers are therefore offered an unlimited lens choice, with complete lens metadata accessible from LDS-2, LDS-1 or /i lenses.
For even further cross-system compatibility, an LPL lens mount can be fitted to existing ALEXA, ALEXA Mini and AMIRA cameras. ARRI Signature Primes and other future LPL mount lenses can therefore be used for both Super 35 and large format on productions combining the two.
ALEXA LF is based on the proven, robust ALEXA camera design, so all existing accessories will work right out of the box. Since all other features and the user interface are the same as in the ALEXA SXT W—including the integrated wireless video transmitter and the user interface—crews will adapt quickly.
ALEXA LF offers the same tried-and-true, versatile workflows as other ALEXA cameras. Following the 16-bit internal image processing, recording at various resolutions is possible in uncompressed, unencrypted ARRIRAW or fast, efficient ProRes. Existing ARRI Look Files can be used with ALEXA LF, and the entire range of ARRI workflow software tools supports ALEXA large-format images. Lens metadata can be recorded from LDS-1, LDS-2 or /i capable lenses.
Q: What is the difference in sensor size between the ALEXA 65, ALEXA LF, and ALEXA SXT W?
A: The ALEXA LF has a sensor twice as large as ALEXA SXT Open Gate, and ALEXA 65 has a sensor three times as large as the ALEXA SXT. ALEXA LF has the biggest sensor area of any cinema camera for sale, second only to the ALEXA 65, which is a rental-only product.
Q: What recording resolutions are available with the ALEXA LF?
A: The ALEXA LF sensor can be operated in one of three sensor modes: LF Open Gate, LF 16:9, or LF 2.39:1.
In LF Open Gate sensor mode, the entire sensor at 4448 x 3096 can be recorded (native 4.5K).
In LF 16:9 sensor mode there are three options: first, the native 3840 x 2160 (UHD) can be recorded. Second, the camera can downscale 3840 x 2160 to ProRes 16:9 2K (2048 x 1152). Third, the camera can downscale 3840 x 2160 to ProRes 16:9 HD (1920 x 1080). Those downscale options are there if you want to reduce the data rate and have no need for the higher resolutions.
In LF 2.39:1 sensor mode, the sensor area of 4448 x 1856 can be recorded (native 4.5K).
Q: Is the ALEXA LF camera Netflix compatible?
A: Yes. Netflix has tested the ALEXA LF and confirmed it meets the required standards for capture and recording. More specifically, Netflix stated that the ALEXA LF is compatible in all three sensor modes (LF Open Gate, LF 16:9 and LF 2.39:1) and recording ARRIRAW or ProRes Log C. The Alexa LF is listed on the Netflix ‘Prodicle’, “Help Center Support Page”:
Note: There are lens combinations that could fall out of the approved Netflix specifications.
Q: What are the maximum frame rates of the ALEXA LF with SxS cards?
A: The maximum frame rate with SxS PRO+ 256 GB cards is 90 fps in ProRes.
Q: Will ALEXA LF be compatible with existing postproduction tools, like Baselight, DaVinci Resolve, Colorfront OSD, or Codex Production Suite?
A: Yes, ARRI is working closely with all members of the Partner Program on updating their tools as soon as possible. For instance, in February, Codex plans to release an update to their Codex Vault Platform Production Suite. If you are planning a production with ALEXA LF, check with your post house to make sure that their tools have been updated with ALEXA LF compatible versions. ARRI will release, as usual, sample clips of ALEXA LF footage in ARRIRAW and ProRes for testing.
Q: Can I make my own framelines for the ALEXA LF?
A: Yes. In addition to the default framelines built into the camera, there is also the online ARRI Frameline Composer which allows the creation of any frameline your heart desires.
Q: Can I record MXF/ARRIRAW with the ALEXA LF?
A: No. At this point in time the ALEXA LF records the traditional ARRIRAW (.ari), which is the same format recorded by the ALEXA Classic, ALEXA XT and ALEXA SXT family of cameras.
Q: Does ProRes recording to SXR Capture Drives on the ALEXA LF work like it does on the ALEXA SXT W?
A: SXR Capture Drives used with the ALEXA LF will have the same ProRes recording behavior as in ALEXA SXT W: ProRes is RAID and the drives have half their nominal capacity.
Q: Why do you not support XR Capture Drives, CFast 2.0 cards or the smaller capacity SxS PRO cards anymore?
A: This is because the slower and smaller capacity media don’t make sense with the higher data rate of ALEXA LF, and because Arri wanted to reduce complexity and testing time.
Q: What is the size of the ALEXA LF?
A: The ALEXA LF is significantly smaller than the ALEXA 65, and only 12 mm longer and wider than the ALEXA SXT W.
Q: What does the ALEXA SXT W do that the ALEXA LF does not do?
A: While there is a large overlap between ALEXA LF and ALEXA SXT W cameras, there are still some things the ALEXA SXT W is capable of that are not available from the ALEXA LF.
In-camera anamorphic de-squeeze in 2k and 4K
Many more bespoke recording formats
Support for XR Capture Drives, CFast 2.0 cards, and older SxS PRO and SxS PRO+ cards
Higher ProRes frame rates for the Super 35 sensor area. For instance, for ProRes 4444XQ, the ALEXA LF provides a maximum frame rate of 60 fps, while the ALEXA SXT W can record ProRes 2K 4444 XQ up to 120 fps.
For any show that does not require the look of large-format or 4K, the ALEXA SXT W remains Arri’s top-of-the-line Super 35 camera.
Q: Does the ALEXA LF support WiFi Client mode?
A: Neither the ALEXA LF nor the ALEXA SXT W support WiFi client mode.
Q: Does the ALEXA LF support cforce motors?
A: No. The ALEXA LF is based on the ALEXA SXT, which does not support the LBUS connector that is required for cforce motors. Arri considered including LBUS support in ALEXA LF, but decided against it since it would have required major changes to the entire electronics architecture and would have significantly delayed the availability of the camera. However, the ALEXA LF does support the ARRI CLM motors of which there are many available in rental houses worldwide.
Q: Why is the ALEXA LF not an 8K camera?
A: Arri firmly believe that image quality is not just about resolution, but consists of other parameters that, one could argue, are more important than resolution. Dynamic range, for instance, has been a very important factor that is becoming even more important now that High Dynamic Range Displays are the next new trend. Higher resolution means smaller pixels, smaller pixels receive less light, and therefore have lower dynamic range and more noise than larger pixels. Arri believe in better pixels instead of more pixels.