Arri Alexa Mini compared to Arri Amira
This guide to the Alexa Mini and the Arri Amira has been written by Ian Jackson (assoc. BSC) and is reproduced here with the kind permission of Barry Bassett at VMI Rental
With the introduction of the ALEXA MINI, ARRI have created a camera that addresses a very recent shift in camera requirement for some productions with the proliferation of gimbal rig and drone shots that still demand high end acquisition. This sector has been the domain of RED cameras ever since the introduction of the RED EPIC and SCARLET due to the weight, small form factor and the ability to record in 4K and the MINI is essentially ARRI’s way of packaging an ALEXA to be able to be used in a similar way.
The ARRI AMIRA was introduced about two years ago again as a means to provide ALEXA quality and performance in a smaller more documentary shape and size camera.
This is a short article to highlight the differences and similarities between the two cameras in order to assist VMI clients in making sensible and informed choices about which system would be most suitable for a given project.
"The AMIRA and the MINI are pitched at different working practices and both provide elegant solutions within that and it will be the project you are embarking on that should guide you towards the correct system for you rather than a desire to just use the ‘latest’ versionPhysically the camera bodies are very different from each other because they are designed for different purposes. The AMIRA body is 310mm (approx. 1 foot) long and weighs 4.1kg without any added accessories. The actual shooting dimensions depend on the accessories attached but with batteries, TV logic monitor and Canon 17-120mm zoom with clip on matte box (see photo).
Fully Configured Amira Package. 68cm length, 12.45kg
The length is 68cm and the weight is 12.45kg. However the AMIRA is designed for hand held use and so has some clever features to help the operator ‘tune’ the balance of the camera so the weight is comfortably on the shoulder whilst the viewfinder is in the correct place for the eye. The actual weight is broadly irrelevant as long as the balance of the camera on the shoulder is neutral- i.e. the weight not being supported by the hands and elbows of the operator.
The headline basic weight of the carbon fibre bodied ALEXA MINI is 2.3 kg and it is 185mm long, which is remarkable considering the recording capabilities of the camera….and yet....The MINI is designed for gimbal and drone work and not hand held shots. It can of course be accessorised to become a balanced hand held camera like the AMIRA but that involves the use of a cage system, extra battery outputs and handle kits, so therefore by adding the same kit as the AMIRA above, whilst again ‘tuning’ the accessories to help with the balance the actual working length is 78cm and the working weight is 12.5kg.
Fully configured Alexa Mini 78cm long, 12.5kg
One of the main issues with the MINI is providing power for accessories as the on board power out options are very limited, this involves a bar mounted battery plate which can supply either D-Tap or RS outputs (see photo). As the MINI CFast card slots are at the rear of the body, any battery plate has to be sufficiently distant from the back of the camera to allow the operator sufficient space to be able to change cards. The drawback is that this necessarily extends the length of the camera but paradoxically the benefit of this arrangement means that the battery plate and batteries are placed away from the back of the camera body in order to assist with maintaining neutral balance with a lens like the Canon 17-120mm. Therefore for a given set of accessories, the AMIRA and ALEXA MINI pretty much weigh the same but the ALEXA MINI is 10cm longer when configured for comfortable and balanced hand held use ( the additional battery is used is a counterbalance as there is no actual real weight in the body-and a Dionic HC weighs 700g approx).
If your project is mainly hand held, run and gun etc. then the AMIRA is your best option, if you are shooting with gimbals etc. and have plenty of time to rig/de-rig then the MINI is the one for you.
For the sake of balance (pun intended), the figures for an ALEXA CLASSIC with the same kit package for comparison are length 70cm and weight 13.75kg. So the reality is that for most projects for most of the time then a standard Alexa will suffice.
Alexa Classic 70cm length, 13.75kgs
Main Differences between the Mini and Amira
Technically there are some differences between the two cameras that we need highlight here along with a number of identical features.
Sensor wise the AMIRA has a 16:9 super 35mm chip capable of delivering HD, 2K and (up-res’ed) 4K UHD 3840x2160 to a maximum recording codec of ProRes 4444XQ. The maximum fps in HD recording is 200fps and 30fps in UHD 4K (ProRes 4444XQ). The AMIRA also offers the capability to adjust knee, gamma, saturation, black gamma, saturation by hue and ASC CDL parameters and is able to import custom LUTs as .AML files.
Shooting Anamorphic - Mini only
The ALEXA MINI in contrast has a 4:3 sensor which gives it (or will do by April 2016) the capability to use 2x squeeze anamorphic lenses. Additionally and unlike the AMIRA it has the ability to record in both 16:9 and Open Gate ARRIRAW (2.8 and 3.4K respectively) for the ultimate quality of recording similar to that of ALEXA SXT/XT. All other ProRes codecs from HD, 2K etc. are supported by the MINI and it will achieve similar frame rates to that of the AMIRA. The MINI also provides the same gamma, knee etc. adjustments as the AMIRA along with the ability to import 3D LUTS as .AML files. Both cameras offer REC709 and LogC colour gamut with 14 stops of latitude in LogC and both record internally to CFast 2 media which includes the ARRIRAW format on the MINI.
Real World Funcationality
The third aspect to discuss is perhaps the most important as we look at real world functionality. Both cameras have interchangeable lens mounts so can accept PL, EF or B4 type lenses, however it is only the MINI that has a 4:3 sensor capable of working with anamorphic lenses. Both cameras also have adjustable electronic shutters from 5 to 356 degrees. Both cameras will accept 15 and 19mm based base plate systems and both of their shoulder supports are designed as quick release VCT plates as well.
The AMIRA is a balanced, relatively lightweight camera equally at home on the shoulder or on a tripod that is ready to use straight out of the box.
Its versatility is improved by being provided with a choice of 15mm or 19mm bridge plate configurations and also a lightweight camera top or cheese plate, which allows the same camera to be used in a lightweight documentary style or in a fully-accessorised drama-type arrangement with easy substitution of these key items – a luxury not afforded to Mini users.
Amira in lightweight 15mm mode left vs BP-8 mode with cheeseplate top configuration (right)
Amira has four proper XLR sound inputs recording at 24 bit PCM with a sound level monitoring panel and a headphone monitoring mini-jack socket. The AMIRA has a 12 pin Hi-Rose output to interface with ENG style lenses like the Canon 17-120mm along with 24v RS and 12v Lemo 2pin power outputs. There are several assignable shortcut buttons and the main user menu interface is on a small monitor that is part of the viewfinder assembly. The AMIRA also features a set of built in IRNDS up to a maximum of 2.1 (seven stops of exposure control) and has two HDSDI monitoring outputs. The AMIRA does not have any built in wireless LCS functionality and so if the project involves using an ARRI WCU4 wireless system then the AMIRA will need to carry the small additional weight of the UMC4 receiver to work with CLM4 motors or the negligible weight of the AMC1 box which will interface with the smaller Arri CForce motors.
The MINI has to be thought of as a modular camera system that can provide elegant solutions in certain circumstances. At heart it is a small, lightweight carbon fibre box containing a well known and loved sensor and lots of electronics and nothing else. So to turn it into something usable there has to be a building process, firstly to attach the cage accessories that will then allow the other accessories such as the viewfinder, battery and lens control motors to be attached.
This procedure will inevitably take some time to achieve and that will depend on the complexity of the build as certainly for gimbal work the idea would be to keep the weight to a minimum. In all but the previous circumstances, the footprint of a fully functioning MINI is about the same as both an AMIRA and an ALEXA but it presents a couple of challenges when compared to the other systems.
Firstly, the main user menu interface is contained on a screen within the viewfinder housing but if you are not using the viewfinder in an effort to keep the weight down then you have lost the ability to control the camera.
There are two alternatives in this instance, the MINI is supplied with a small Transvideo Starlight touchscreen monitor which provides some limited control over the main parameters such as fps, colour temperature, ISO and shutter angle but the most elegant solution is to use the WCU4 hand unit which can now offer all adjustments via wireless to the MINI. Secondly there is very limited functionality in terms of input and output plugs which has to be addressed by adding third party accessories and battery power and the ability to record sound on board is not really a viable option as the socket provided is non-standard.
Alexa Mini with integrated LCS system in Gimbal configuration
Fully configured Alexa Mini Camera
Neither camera system offers any increase in image quality over a standard ALEXA as all cameras share variations on the same ALEV III sensor and no ARRI cameras currently offer true 4K, only the upscaling options previously mentioned. That said, the ALEXA family of cameras have been by far the most popular choice of high end acquisition for the past six years and with good reason as the image quality and real world functionality as a workable package are still second to none. The AMIRA and MINI are derivations on the original physical form but do not vary particularly from the innovative ALEXA look so again for a large percentage of projects an ALEXA will serve just as well as an AMIRA or a MINI.
The AMIRA and the MINI are pitched at different working practices and both provide elegant solutions within that and it will be the project you are embarking on that should guide you towards the correct system for you rather than a desire to just use the ‘latest’ version because it’s there. In conclusion below are a few basic parameters that may guide you towards the system you require and of course VMI rental staff are on hand to help discuss your needs.
|I'm shooting HD at ProRes 4444||Amira / Alexa|
|I'm shooting mainly on a drone||Mini|
|I'm shooting mainly hand held||Amira / Alexa|
|I'm shooting on a dolly with all the toys||Amira / Alexa|
|I'm shooting ProRes 4444XQ||Amira / Mini|
|I need a lightweight B camera||Mini|
|I'm shooting ARRIRAW||Mini|
|I'm shooting with anamorphic lenses||Mini / Alexa|
|I need to record sound on board||Amira|
|I'm shooting with an ENG style lens||Amira|
Ian Jackson (Assoc. BSC) March 2016