ALEXA LF FAQ
Learn more about the ALEXA LF
Learn more about the ALEXA LF
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. ALEXA LF can be operated in one of three sensor modes: LF Open Gate, LF 16:9 and LF 2.39:1.
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.
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 (4K UHD). 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.
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 sensuous 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) image areas fit within the image area recorded in this sensor mode.
Yes. At the same T-stop, a lens that provides the same angle of view as on a Super 35 sensor will have about one stop less depth of field, and the higher resolution of the ALEXA LF will also reveal focus issues that may have been masked by the lower resolution of a Super 35 sensor.
Using a WCU-4 can make focus pulling easier, and the ZOOM function for EVF and MON OUTs can help checking focus. The EVF-2 provides higher resolution and higher contrast than the EVF-1, which also help to judge focus better.
The maximum frame rate of the ALEXA LF is dependent on three factors:
1. the sensor mode (LF Open Gate, LF 16:9 or LF 2.39:1),
2. the codec (ARRIRAW or Apple ProRes) and
3. the recording medium (SXR Capture Drive or SxS PRO+ 256 GB card).
When no recording medium is inserted, the ALEXA LF will allow you to set the maximum frame rate that is possible in the currently set sensor mode, irrespective of the recording medium or the codec.
Once a recording medium is inserted, the ALEXA LF will show you the maximum fps possible with the set sensor mode, set codec and the inserted medium. For example, if no medium is inserted and the ALEXA LF is set to LF Open Gate sensor mode and the Apple ProRes codec, it will show the maximum frame rate possible in LF Open Gate, which is 90 fps. Once you insert an SXR Capture Drive, it will show the maximum frame rate possible with LF Open Gate, Apple ProRes and an SXR Capture Drive, which is 60 fps.
There are five different recording resolutions available to provide just the right solution for any production and budget.
Yes. ALEXA LF is Netflix approved in all three sensor modes (LF Open Gate, LF 16:9 and LF 2.39:1) and in ARRIRAW and ProRes (4444 XQ, 4444 and 422 HQ) recording formats. The ALEXA LF is listed on the Netflix "Help Center Support Page".
Note 1: While full frame lenses cover the full ALEXA LF sensor in all three sensor modes, many Super 35 spherical lenses also cover the LF 16:9 sensor mode, including:
Note 2: While full frame anamorphic lenses are slowly entering the market, shooting with existing 35 format anamorphic lenses is also possible by using LF Open Gate and cropping the desired area from the image in post-production. A Netflix approved ARRI white paper with details can be downloaded directly here.
Amongst other topics, the white paper covers two methods for shooting with anamorphic lenses for a 4K mandate:
Note 3: Netflix recommends that lenses not specifically designed for large format be thoroughly tested for adequate sensor coverage, and for satisfaction of the production’s creative intent. To check the illumination of different lenses on ARRI cameras, please try the Frame Line & Lens Illumination Tool.
Note 4: Please note that the UHD SDI output of this camera is also approved by Netflix and has already been used in a number of projects.
Yes. Since the ALEXA LF is only slightly larger than the ALEXA SXT, it is no problem. And having the wireless video integrated makes the rig more symmetrical and tidier. You do have to pay attention, though, to the camera's power input requirements. ALEXA LF is a 24V camera; it will accept 18.5 to 34 V through the on-board battery interface and 19.5 to 34 V through the BAT connector, and it needs between 120 W and 160 W depending on set up and connected accessories.
During manufacturing of the camera and after certain service procedures, the sensor of the camera will be calibrated. The calibration maps the sensor’s response to light for proper sensitivity, brightness and dynamic range for all color channels, red, green and blue. This is an absolute necessity in order to create a stable and reproducible image coming from a digital sensor.
While there is a large overlap between ALEXA LF and ALEXA SXT W cameras, there are still some things the ALEXA SXT W does that are not available from the ALEXA LF.
For any show that does not require the look of large format or 4K, the ALEXA SXT W is our top-of-the-line Super 35 camera.
We firmly believe that image quality is not just resolution but consists of other parameters that are arguably more important than resolution. Dynamic range, for instance, has been a very important factor that is becoming even more important now with High Dynamic Range displays are the next big trend. Going for higher resolution would mean using smaller pixels, which in turn would receive less light, and so would have lower dynamic range and more noise than larger pixels. We believe in better pixels instead of more pixels.
Yes, from LF SUP 4.0 on, the ALEXA LF supports EXT Sync. Like in the Super 35 ALEXA cameras, the ALEXA LF supports precise synchronization of two sensors (Sensor Sync) and of the settings of two ALEXA LF cameras (Settings Sync) for 3D shooting or other applications that require a tight synchronization of the sensors.
Temporal noise reduction, as used in the ALEXA SXT, looks at the frames before and after the target frame to reduce noise. New in the ALEXA LF is Enhanced Motion Detection (EMD), which is possible because the ALEXA LF has more processing power than all previous ALEXA cameras. EMD additionally checks the pixel behavior around each pixel and thereby avoids temporal artifacts in high motion areas. This feature is newly introduced with the ALEXA LF to make noise reduction more robust for footage with high motion.
Noise reduction, when turned on, is baked into ProRes but not baked into ARRIRAW. It is, however, recorded as metadata in ARRIRAW. Please note that in general, we recommend not using noise reduction in-camera but rather use noise reduction in post, as there are more options to customize the type of noise reduction in post.
All ALEXA cameras actively keep the sensor at a stable temperature for best overall image quality. ALEXA Classic, XT, SXT and SXT W cameras keep the sensor at 35º C. In rare cases in high humidity environments, this could lead to condensation on the sensor. Therefore, these cameras have a "High Humidity" sensor temperature option that allows the sensor to run a little hotter to avoid condensation. With ALEXA LF we have found a way to always run the sensor at a higher temperature, and therefore do not need a special high humidity mode.
The screws have no relevance for the user. They allow us to adjust the sensor coplanarity (the sensor surface being perfectly parallel with the lens mount surface) in manufacturing. These three screws are not the actual adjustments but rather capping screws and there are no user-serviceable parts inside.
Yes. Sensors are different from the human eye, and even in environments that are nominally safe for humans (like a laser show, for example), it is possible to damage the sensor with a laser beam. If and how the sensor is damaged depends on a number of factors, including the lens' focal length, lens iris setting, lens focus setting, the laser power, projected pattern and for how long the sensor is exposed to which part of the laser pattern.
Yes, for a stable and clean signal, a 4.5 GHz cable is mandatory. You can use this cable (also sold by ARRI): "Belden Video Brilliance 1505F HD-SDI High Flex Precision Video Cable 4.5 GHz", or any other cable meeting the same specifications.
Yes, the ALEXA LF can load an ARRI Look file for HDR monitoring in either PQ or HLG. This works with the HD and UHD MON OUT settings either through the BNC outputs or the built-in wireless video transmitter.
The ZOOM feature is designed for a temporary zoom-in to quickly check focus. In LF SUP 3.0, it is improved with six user-settable target areas. While ZOOM on the EVF can be accessed as always through the dedicated ZOOM button, the ZOOM feature on the MON OUT paths can be managed through three ZOOM user buttons:
An activated ZOOM is indicated by an orange outline around the image, to make sure no one mistakes the zoomed in image for the proper image.
MON OUT 1 and MON OUT 2 can each output either
MON OUT 3 can output a 422 1.5G single link HD-SDI signal. The signals going to the three MON OUTs can each have the following processing applied to the monitoring path: Log C, Look File or ALEXA Classic 709. All three MON OUTs can be set to output in either Rec 709 or the Rec 2020 color space, independently of the monitoring path processing.
Yes. A number of common framelines for large format and Super 35 are accessible from the ALEXA LF menu under MONITORING>FRAMELINES. Custom framelines can be created with the online ARRI Frame Line and Lens Illumination Tool.
In order to provide ALEXA best image quality at higher pixel counts, ALEXA LF has a higher power draw than previous ALEXA cameras.
- while recording ProRes 4444
- in LF 16:9 sensor mode
- at 24 fps
- onto SxS PRO+ 256 GB cards
- with EVF-1 and wireless video transmitter on,
- but no further accessories attached.
- while recording ARRIRAW
- at 90 fps
- in LF Open Gate sensor mode
- onto SXR Capture Drives
- with EVF-1 and wireless video transmitter on,
- but no further accessories attached.
Note: electronic accessories will increase power draw based on the accessories’ power draw.
Unfortunately, the AMIRA and ALEXA Power Supply Light (K2.0006876) is not suitable to power the ALEXA LF. While it works fine in situations that demand little power, it may not work in situations that demand a lot of power. Do not use this power supply with the ALEXA LF.
We recommend using the Power Supply NG 12/26 R (K2.47351.0) to power the ALEXA LF. Unfortunately, it is not available for sale anymore, due to discontinued parts of the supplier. We are currently working on a replacement option.
Yes. The power draw of the ALEXA LF is no problem for existing 24V block batteries that are attached with a cable to the ALEXA LF BAT connector.
The top end of the ALEXA LF power draw from a 12V on-board battery would generate currents that various components in the camera/battery-adapter/on-board-battery system are not rated for.
The power input of the ALEXA LF has been set to 18.5 - 34 V for the on-board battery interface (19.5 to 34 V for the BAT connector). The current ALEXA battery adapters for 12V Gold mount (BAB-G K2.72003.0 and BAT-G K2.72006.0) and 12V V Lock (BAB-V K2.72010.0 and BAT-V K2.72011.0) will not work with the ALEXA LF.
However, there are three alternative battery adapters offered by ARRI: the "Battery Adapter Back High Load Gold Mount" (BAB-HG), the "Battery Adapter Back High Load V Mount" (BAB-HV) and the "RP-CFA1" battery adapter. Additionally, there is a range of other options are available from third party on-board battery manufacturers. An overview of all on-board battery solutions for ALEXA LF can be found in the Technical Info "ALEXA LF & On-board Batteries".
The "Battery Adapter Back High Load Gold Mount" (BAB-HG) and the "Battery Adapter Back High Load V Mount" (BAB-HV) are designed for Bebob 14.4V ACINE (Gold Mount) and VCINE (V Mount) on-board batteries. The ACINE and VCINE on-board batteries are compatible with existing 12V battery adapters and chargers. The ARRI BAB-HG and BAB-HV battery adapters boost the batteries' voltage to 20 V so it is acceptable for the ALEXA LF and extra pins on the batteries provide sufficient current to power the ALEXA LF. For more information on the batteries, take a look at http://bebob.de/en/acine.html and http://bebob.de/en/vcine.html. Please note that ARRI is distributing the battery adapters but not the batteries. High Load on-board batteries are being distributed by bebob.
The RP-CFA1 battery adapter is designed for Hawk-Woods 26V Reel Power on-board batteries. The Hawk-Woods 26V Reel Power on-board batteries are being used successfully with the ALEXA 65 and, since the RP-CFA1 is compatible with other ALEXA models, they can also be used with ALEXA Classic, XT, SXT and SXT W. A separate rod mounted Reel Power battery adapter is available for ALEXA Mini. For more information on the batteries, take a look at www.hawkwoods.co.uk/Prods/Product/RP-CFA1 . Please note that ARRI is distributing the RP-CFA1 battery adapter but not the batteries. Reel Power on-board batteries are being distributed by Hawk-Woods.
Yes, since LF SUP 4.0 the ALEXA LF supports ARRI LBUS accessories. By connecting an LCS to LBUS cable (Cable LCS (5p) - LBUS (0.8m/2.6ft) - K2.0007318) to one of the two LCS connectors on the ALEXA LF, it is now possible to use the majority of ARRI LBUS accessories with the ALEXA LF. LBUS devices can daisy chain, but it is also possible to connect one cable each to the two ALEXA LF LCS connectors to support even more LBUS devices.
LBUS accessories compatible with ALEXA LF are:
- Needs cforce mini RF SUP 1.1
- The cforce mini RF motor must be set to "client mode". Then it works like a cforce mini motor without the RF functionality, which the ALEXA LF has built-in anyway.
- Needs at least Master Grip/OCU-1 SUP 1.1.2
- For override function it needs Master Grip/OCU-1 SUP 2.0
- Needs Master Grip/OCU-1 SUP 2.0
- With the CUB-1 it is possible to connect an ARRI Ultrasonic Distance Measure (UDM) to an LBUS connector. While a different cable can also connect the UDM directly to the ALEXA LF EXT connector, the CUB-1 option might come in handy if the EXT connector is in use otherwise (e.g. for sensor sync, for instance).
- The CUB-2 allows an ARRI LBUS device (for instance the Master Grips or Operator Control Unit OCU-1) to control the internal motors in ENG lenses.
Please note that when using cforce motors with ALEXA LF, separate power must be provided to the cforce lens motors from the other side of the daisy chain, for instance from an LBUS to D-tap cable (LBUS - D-Tap - K2.0006758) connected to an on-board battery. This is because the power output from the ALEXA LF LCS connectors cannot provide sufficient power to the cforce motors. If cforce motors are powered from the LCS connectors, calibration may malfunction, fast motor movements may result in stuttering motor movements and a whining noise could be generated during slow motor speeds.
Please note that for OCU-1 override function, the WCU-4 needs WCU-4 SUP 3.2 (planned for Q4 2018).
Yes. The tape hook of the Handle Extension Bracket HEB-2 is still aligned with the sensor plane of the camera.
The following accessories are not compatible with ALEXA LF cameras (in contrast to ALEXA SXT W):
- Battery Adapter Back for Gold mount (BAB-G K2.72003.0 and BAT-G K2.72006.0)
- Battery Adapter Back for V Mount (BAB-V K2.72010.0 and BAT-V K2.72011.0)
- Battery Adapter Top for Gold Mount BAT-G (K2.72006.0)
- Battery Adapter Top for V Mount BAT-V (K2.72011.0)
- Use internal LF FSND filters instead (included with ALEXA LF Pro sets)
- Note: S35 ALEXA cameras equipped with an LPL lens mount need special "LPL S35 FSND filters"
When first released, the ALEXA LF (with Software Update Package (SUP) 2.0 or 2.1) could record to SXR Capture Drives 1TB and 2 TB (ProRes or ARRIRAW). Since LF SUP 3.0 it can also can record to SxS PRO+ 256 GB cards (ProRes only).
This is because the slower and smaller capacity media don’t make sense with the higher data rate of ALEXA LF, and because we wanted to reduce complexity and testing time.
Yes, most post production tools have been updated to support ALEXA LF material.
Live grading on set with the ARRI Look Management is supported by Pomfort LiveGrade, Codex Live, Colorfront On-Set Live, Filmlight Prelight, Technicolor DP Lights and others.
Automated dailies creation with the ARRI Look Management is supported by DaVinci Resolve, Colorfront OSD, Codex Production Suite, Pomfort Silberstack, Filmlight Daylight and others.
Editing with looks through the ARRI Look Management is supported by Avid Media Composer, Apple Final Cut Pro X and Adobe Premiere.
In all cases, check with the manufacturer to make sure you have the software version that supports the ARRI Look Management.
Yes. Recording ARRIRAW with the ALEXA LF works exactly the same as recording ARRIRAW with ALEXA XT, SXT or SXT W cameras. The same hardware tools, software tools and methods can be used. As with the other ALEXA cameras, SXR Capture Drives can record ARRIRAW or ProRes, and SxS PRO+ cards can record ProRes but no ARRIRAW.
High Density Encoding (HDE) is a technology developed by Codex that reduces ARRIRAW file sizes by 40% during download or later in the workflow process. Important note: HDE does not happen in-camera. Inside the camera, ARRIRAW gets recorded in full size onto the Compact Drive. Only during the download process from the Compact Drive to a computer is the data encoded with HDE. HDE is part of the free-of-charge and license-free Codex Device Manager software. HDE is fast: ARRIRAW Open Gate 4.5K can be encoded comfortably at 24 fps on a modern MacBook Pro. Many third parties already support HDE, including Assimilate, Codex, Colorfront, Filmlight, Imagine Product, Pomfort, YoYotta, Marvel, Netflix, Fotokem, Sony and others. Codex and ARRI are actively working with industry partners on integrating HDE into many more tools. In summary, HDE is a direct 40% savings in time and money through lower storage costs, shorter transfer times and a faster workflow.
To learn more about HDE have a look at our ARRIRAW FAQ and filter for High Density Encoding (HDE).
Also pay a visit to the HDE website of CODEX.
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. It does not record MXF/ARRIRAW.
Yes. SXR Capture Drives used with the ALEXA LF will have the same ProRes recording behavior as with the ALEXA SXT W: ProRes is recorded in a RAID configuration and the same hardware tools, software tools and methods can be used. As with the other ALEXA cameras, SXR Capture Drives can record ARRIRAW or ProRes, and SxS PRO+ cards can record ProRes but no ARRIRAW.
The UDF file system used by all ALEXA cameras (except for ALEXA Mini) for ProRes recording has a QuickTime/ProRes file size limit of 229 GB. This limits the length of each clip based on the sensor mode/fps settings. This is the same for SXR Capture Drives and SxS PRO+ cards.
ProRes RAW is a new addition to the family of ProRes Codecs which is in its early stages and we are currently looking into it.
Neither the ALEXA LF nor the ALEXA SXT W support WiFi client mode.
Export laws dictate that for sensors made up of more than a certain number of photo sites, we cannot record positional information like tilt and roll, lest the camera be classified as military equipment. This rule looks at the total number of photosites on the sensor and does not concern itself with individual recording formats that may record fewer photosites. While the photo site count of the Super 35 ALEXA, ALEXA Mini and AMIRA cameras falls below this boundary, the ALEXA LF and ALEXA Mini LF are above it. However, we can display the tilt and roll information as well as the digital bubble level.
Since the display used in the EVF-1 has been discontinued, a new viewfinder - the EVF-2, has been developed to accompany the ALEXA LF. While still maintaining its predecessor’s proven robustness, reliability and ergonomics, the EVF-2 is equipped with a new display with full HD resolution and higher contrast, improving the operator's ability to judge focus and dynamic range.
We have taken the opportunity to also include a new glass eyepiece based on the ARRICAM design for a cleaner image which is free of distortions, and which allows greater freedom of movement for the operator through a wider exit pupil.
And while we were at it we have implemented the latest color science, which gives more accurate color rendition, a better match to on-set monitors, and a stable color balance at all display brightness settings, image brightness levels and from -20ºC to +45ºC (-4º F to +113º F).
For those who use EVF-1 and EVF-2 on the same set, an "EVF-1 gamma" setting emulates the EVF-1 tonal behavior.
The EVF-2 requires an ALEXA LF with software LF SUP 3.0 or later. All ALEXA LF cameras shipping from availability of LF SUP 3.0 on will be delivered with the EVF-2. The EVF-2 will not work with ALEXA LF with LF SUP 2.0/2.1 or with any other ALEXA model.
Yes. ALEXA LF cameras from LF SUP 3.0 on are compatible with EVF-1 and EVF-2.
Yes. Since a hardware upgrade from EVF-1 to EVF-2 is not feasible, owners of ALEXA LF/EVF-1 can acquire the EVF-2 by trading in their EVF-1 and paying half the EVF-2 list price.
The new POWER setting in the camera's EVF menu selects the EVF-2 display mode.
The new GAMMA setting in the camera's and the viewfinder's EVF menu selects the EVF-2 gamma characteristic.
A larger sensor needs a larger lens mount for optimal lens design. The LPL lens mount allows the design of full-frame lenses that are smaller, lighter and have a faster T-stop than equivalent lenses designed for the smaller PL lens mount. The traditional PL mount would compromise modern full-frame lens design; its diameter was based on the Super 35 sensor size and its long flange focal depth was dictated by the fact that film cameras had a mirror shutter.
Yes. The LPL mount is a key element of the ARRI large format system. Since we know that customers will not always use ARRI cameras and/or ARRI lenses, but we did not want to limit our customers' choices, the LPL mount comes in a number of versions and is licensed to other camera and lens manufacturers.
There currently are three versions of the LPL lens mount supplied by ARRI. The "LPL Lens Mount for ALEXA" works on ALEXA Classic, XT, SXT, SXT W and LF cameras. The "LPL Lens Mount for ALEXA Mini/AMIRA" can be used on ALEXA Mini and AMIRA. However, the LBUS connector on this mount will only work on an ALEXA Mini, not on AMIRA. The "LPL Mount for ALEXA 65" can be used on the ALEXA 65. In addition, we are licensing the LPL mount to other camera manufacturers.
A number of companies have announced that they are planning to equip lenses with the LPL Mount, including Angenieux, ARRI Rental, CW Sonderoptic/Leica, Cooke, Panavision, Vantage, Zeiss and others.
The PL-to-LPL Adapter allows the use of Super 35 PL mount lenses and of full frame PL mount lenses.
Yes, the existing PL lens mount fits on the ALEXA LF as well. However, in tests we have found that a combination of LPL lens mount and PL-to-LPL Adapter lets more light through in the corners than the PL lens mount on its own, so we recommend always using the LPL lens mount with PL-to-LPL adapter for PL lenses. Below is an example shot with an ALEXA LF and a Master Prime 65 mm lens.
The LPL lens mount has a flange focal depth of 44mm for two reasons: first, an optical design study concluded that a 44mm flange focal depth and 62mm diameter allow for ideal optical designs for large format lenses; second, it provides enough room to create LPL mounts for ALEXAs, ALEXA Minis, AMIRAs and third party cameras and has enough space for the PL-to-LPL adapter.
The LPL lens mount on the ALEXA LF accepts LDS-2 and Cooke /i lens metadata signals.
The PL-to-LPL Adapter supports both LDS-1 and Cooke /i lens metadata signals. Because the adapter has two sets of contacts on the camera side, it can be inserted into the LPL mount in two positions: either so the contacts are in the 12:00 o'clock position for ARRI lenses (left image), or so that the contacts are in the 3:00 o'clock position for Cooke lenses (right image). In both positions the adapter supports LDS-1 and Cooke /i.
Yes. The PL-to-LPL Adapter has been designed so that there is ample room behind it for the Large Format Full Spectrum Neutral Density (LF FSND) filters. Please note that the PL-to-LPL Adapter has to be removed to change LF FSND filters.
Please note that the PL-to-LPL Adapter has been designed for Full Format and Super 35 PL mount lenses. Most Super 16 PL lenses will probably not work, since they reach deeper into the camera. Also, some re-housed Super 35 PL mount lenses or exotic lenses may not work. If you are unsure, you can use the Depth Gauge DG-1 to measure it, it is included in the ALEXA LPL LF FSND Filter Set. If you would like to read more about this topic, the ALEXA LF Manual includes a lot of information in chapter 14.1.
A Large Format Full Spectrum Neutral Density (LF FSND) 1.2 filter is pictured below.
Yes, a PL-to-LPL Adapter fits securely into the LPL mount and allows the use of Super 35 PL mount lenses or full frame PL mount lenses. This adapter ships with each camera and allows fast switching between PL and LPL mount lenses on set. Since the adapter is a mechanical device with no optics, there is no light loss when using it.
Yes, the use of anamorphic lenses on ALEXA LF is easy. There are three main use cases for anamorphic lenses on ALEXA LF: using full frame anamorphic lenses, using 35 format anamorphic lenses with a 4K mandate and using 35 format lenses to match a Super 35 ALEXA.
The use of existing 35 format anamorphic lenses for a native 4K mandate is also possible by using LF Open Gate and cropping the desired area from the image in post-production. A Netflix approved ARRI white paper with details can be downloaded directly here.
Amongst other topics, the white paper covers two methods for shooting with anamorphic lenses for a native 4K mandate:
Yes. ALEXA LF can de-squeeze images from all current anamorphic squeeze ratios (1.25x, 1.30x, 1.50x, 1.65x, 1.80x and 2.00x) on the viewfinder and monitor outputs. These de-squeeze factors cover most currently available anamorphic lenses and are available in all sensor modes. From LF SUP 3.0 on, the de-squeeze ratio is set once in the PROJECT settings. This de-squeeze ratio can be activated or deactivated individually for each of the four monitoring image paths (EVF, MON OUT 1, 2, 3). This de-squeeze ratio will be recorded in metadata and used for automatic de-squeeze in the ARRIRAW Converter and other postproduction tools.
Please note that, while the ALEXA LF will happily de-squeeze anamorphic images for the viewfinder and MON OUT image paths, it will not perform any de-squeezes on the recorded image. The ALEXA LF records exactly what the anamorphic lens projects onto the sensor, which is the squeezed image.
Yes. There are many methods for using Super 35 lenses with the ALEXA LF. The three most common ones are: Using the wide illumination area of ARRI Super 35 lenses, using an image expander and cropping the Super 35 area in post.
Any lens projects an image with a circular (spherical lenses) or oval (anamorphic lens) shape onto the sensor. Inside this shape is the image area, which is the area within which the lens’ manufacturer guarantees the lens optical quality. However, there is still light outside the image area, all the way out to where there is no more light, which is called the illumination area. Both areas of most ARRI lenses are very large, since we wanted to make sure that if a customer shot Super 35 on a film camera but had forgotten to switch the lens mount from N35 to S35, they would still get an image. Because of that our lenses have bigger image and illumination areas than most other Super 35 lenses.
In tests, we found that the illumination area of many ARRI Super 35 lenses cover the LF 16:9 sensor mode (UHD - 3840 x 2160). Therefore, a production can be shot mostly with those lenses and use maybe one or two Signature Primes or the Ultra Wide Zoom 9.5 - 18 for wide-angle shots.
More information on which lens covers what can be found in the online ARRI Frame Line and Lens Illumination Tool. Based on the information available there, we have found that the following ARRI Super 35 lenses cover the LF 16:9 sensor mode:
Below an example of the Master Prime 35 mm lens, the widest Master Prime that covers the LF 16:9 sensor mode. Note that a Master Prime 35 mm used with the LF 16:9 sensor mode has the same horizontal angle of view as a Master Prime 26 mm used with the Super 35 2.8K sensor mode (1.33x conversion factor).
You can use a third-party image expander that will optically magnify the image to cover the full sensor in LF Open Gate sensor mode. This works with some spherical as well as with some anamorphic 35 format lenses. It will maintain the angle of view and depth of field of the 35 format. However, you should be aware of a number of issues.
Using the LPL lens mount and the PL-to-LPL Adapter, it is possible to shoot with a Super 35 lens and crop the image in post. This works great for anamorphic and spherical lenses.
Basically, expanders and extenders perform the same function: they magnify an image. The difference lies in the intent.
Good question and a source of much confusion. There are three terms that play into the answer: focal length, sensor size and angle of view. Let’s start with focal length, which is defined as the distance from the optical center of the lens to the sensor when the lens is focused at infinity. Focal length is a property of the lens, and always stays the same. A 50 mm lens is always a 50 mm lens and will always project an image of the same size into the camera. This is where the sensor size comes in; ARRI uses three sensor sizes in cameras: 35 format, large-format (aka full frame) and 65 format. They determine how much of the image projected by a 50 mm lens you actually capture. A large format sensor will capture more image than a 35 mm sensor. The result is expressed as angle of view, how much image you capture. Let’s say you use a 50 mm lens to shoot a landscape with a tree in it. Put that lens on a 35 mm camera, and you may just get the tree in. A large format camera will show the tree and a lot of surrounding landscape. Not because the lens is doing anything different, but because the sensor can grab more of the image created by the lens. This means that if you want to capture the same angle of view with a large format camera as you would have with a Super 35 camera, you need to use a lens with a longer focal length on the large format camera.
That depends on whether the lens has the corresponding lens mount and if it projects an image circle big enough for large format or the 65 format. Many Super 35 format lenses do not project an image circle large enough to cover large format; these will show vignetting. The amount of vignetting can be seen with the online ARRI Frame Line and Lens Illumination Tool.
The crop factor is a number used to calculate what focal length lens to use to get the same angle of view for different sensor sizes. Calculating the crop factor for two sensor sizes is relatively easy, assuming both sensors have the same photosite size (all ARRI digital cameras do). The crop factor is the larger horizontal photosite count divided by the smaller horizontal photosite count. So, if we wanted to calculate the crop factor for the ALEXA LF "LF Open Gate" sensor mode and the ALEXA SXT "S35 Open Gate" sensor mode, we would divide 4448 by 3424, which equals 1.3. This means that to get the same angle of view of a 50 mm lens on S35 ALEXA Open Gate, you need a 65 mm lens on LF Open Gate (50 x 1.3 = 65). Or, the other way around, to get the same angle of view of a 65 mm lens on LF Open Gate, you need a 50 mm lens on S35 Open Gate (65 / 1.3 = 50).
Note: for sensors with photosites of different size, simply use the width in mm of the active photosites for calculating the crop factor.
Not at the moment. We would have to build a special Leica M lens mount, which we will do if there is enough demand.
It might be possible, but we would need to create a new lens mount, since the flange focal depth of still photo lenses would not permit an adapter.