Choosing Cameras

Thoughts on the Arri ALEXA 65 65mm 6K Camera

My thoughts on the Arri Alexa 65 65mm 6.5K cinema camera. Who is it for?

Very quietly, like a tip-toing Titansaur, Arri ushers in the next generation of cinema. Strictly speaking, though, this is a road already travelled:

  • 65mm film cameras exist already. Arri makes them too.
  • It is out-muscled by true IMAX film
  • A 65mm digital camera was already released years ago by Vision Research, the Phantom 65. Now discontinued.

But the Arri Alexa 65 camera is special. It is not a dinosaur, nor is it a scientific camera or experiment. It is a definitive statement by Arri. If cinema must survive, it must get bigger, as I’ve written here.

This article represents my thoughts on the new Arri Alexa 65 and its possibilities for future cinema.

Exclusive Bonus: Download my cheatsheet (with examples) of tried and tested ways to cover a scene or action that will save your skin when your mind goes blank (PDF file optimized for mobiles and tablets).

What is the Arri ALEXA 65?

On the outside, it looks like a bigger version of the Arri Alexa XT, the best camera in the world as of 2014:

Arri Alexa 65

The difference is on the inside. Here are the official specifications (important ones highlighted in color):


Camera type 65 mm format digital cinema camera
Sensor ARRI A3X CMOS sensor
Image aperture 5-perf 65 mm (54.12 mm x 25.58 mm active image area)
Sensor resolution 6560 x 3102 (Open Gate – maximum recordable)
Dimensions Length: 387.8 mm | 15.3 in
Width: 208.3 mm | 8.2 in
Height: 163 mm | 6.4 in
(body only with XPL mount)
Weight 10.5 kg | 23.2 lb
Lens mount ARRI XPL mount with Lens Data System (LDS) functionality
Shutter Electronic, 5.0º to 358.0º. Adjustable with 1/10º precision.
Frame rates 20 to 27 fps (Open Gate) *
Exposure index EI 200 to EI 3200. Base sensitivity EI 800
Dynamic range >14 stops

Recording system

Recording file format Uncompressed ARRIRAW
Recorder crop modes 5-perf 65 mm (Open Gate, 1.78 extraction)
8-perf 35 mm (future)
Storage (type) Codex XR Capture Drive *
Storage (capacity) 480 GByte capacity / 850 MByte per second data rate *
Storage (recording time) 11 minutes @ 24 fps

System interfaces

Viewfinder Electronic color viewfinder ARRI EVF-1
BNC connectors 4 x 3G SDI
 – MON (1) OUT: 2 x 3G SDI
 – MON (2) OUT: 2 x 3G SDI
SD card For software updates and menu settings etc. as with ALEXA
New high speed operating mode for fast ARRIRAW frame grabs (planned feature)
Miscellanous interfaces Focus / iris / zoom motor control with full wireless lens control support
5 x RS 24 V
1 x 12 V
TC I/O (5-pin Lemo)
1 x LDD
2 x LCS
BAT and ACC connection

Monitoring and playback

Monitoring 3 independent color outputs, all with optional overlays:
MON OUT assistive displays:
Zoom, overscan, overlay info, frame lines, false color exposure check, peaking focus check
CDL CDL server support is provided as ALEXA XT
In-camera playback Playback via EVF-1, HD-SDI MON OUT including audio

Open Gate means using the full area of the sensor.

* Upgrade planned for Q1/2015. For more information on specifications, check out the official page.

The most important specifications are the sensor size and resolution. Then comes the lens mount and the data rate. We’ll look at each.

Note: Some sites claim the sensor has been stitched, but it doesn’t look like that from the official image:

Alexa 65 mount XPL sensor 65mm

Either way, it is not something we need to care about, because Arri has hardly ever delivered a dog. For this level of perfection, they also charge the highest! For now, the Alexa 65 is rental-only.

Comparing the sensor of the Arri ALEXA 65 with others

How big is the sensor of the Arri Alexa 65 and how does it compare to its ‘competition’? Here’s a look:

Sensor size comparison Alexa 65 IMAX

The Alexa 65 is the widest sensor (there are some medium format digital sensors out there that are wider, but most of them are older models). It is bigger than traditional 65mm film and even the discontinued Phantom 65.

Here’s a comparison of the crop factor of the Alexa 65 with its most important peers, as well as the aspect ratio (native):

Format H. Crop Factor Native Aspect Ratio
Super 35mm 1.40 Various
FF 35mm 1.00 1.5
Phantom 65 0.69 1.67
65mm 0.67 2.28
IQ280 0.67 1.33
Arri Alexa 65 0.69 2.11
IMAX 0.51 1.34

What does a large sensor imply? Here are some ‘issues’:

  • The lens image circle is way bigger, which means you need medium format lenses
  • For larger apertures, the lenses will be even bigger than their 35mm equivalents. We’re talking bucket-size lenses here. Zooms? Careful what you wish for!
  • The center and corner performances of the lenses must be stellar. Any imperfections will be blown up on 6.5K. There is no hiding place.
  • Poor makeup will be instantly visible. In fact, shooting skin without filtration might end careers.
  • DOF will be shallower, and pulling focus will be a nightmare.
  • The sensor will heat up like an oven. Arri claims the two fans used in this camera are ‘very quiet’, though we don’t know at this stage wether it is quiet enough for audio recording.

Speaking of lenses, here’s what Arri has in store for the Alexa 65:

Arri Hasselblad Lenses Alexa 65

These are rebadged (by IB/E Optics) Hasselblad lenses. The new options are eight primes and one zoom (114mm front diameter):

Lenses 35mm Equivalent Stop Equivalent
24mm T4.8 17 3.3
28mm T4 19 2.8
35mm T3.5 24 2.4
50mm T3.5 35 2.4
80mm T2.8 55 1.9
100mm T2 69 1.4
150mm T3.2 104 2.2
300mm T4.5 207 3.1
Zoom 50-110 T3.5 35-76 2.4

Arri also has a range of Vintage 765 lenses available. For more details, click here. Hasselblad lenses are already famous for IMAX and other 65mm work, being some of the finest lenses on earth. However, they are not the only lenses available.

The Arri Alexa 65 uses a new mount called the XPL mount (eXtra PL?). It has a flange focal distance of 60mm. Here’s how the flange focal distance compares to other medium format lenses:

Mount Flange Focal Distance
Arri PL 52
Leica S 53
Panavision PV 57.15
Mamiya 7/7II 60
Arri Alexa 65 60
Mitchell BNCR 61.47
Hasselblad H 61.63
Mamiya 645 63.3
Bronica 645 ETRS 69
Pentax 645 70.87
Rolleiflex SLX 74
Kiev 60 74.1
Hasselblad 500 74.9
Kowa Six/Super 66 79
Hasselblad/Kiev88 82.1
Pentax 6×7 84.95
Zeiss Ikon Panflex 99.35
Bronica S2A 101.7
Mamiya RZ 105
Mamiya RB 112

Anything greater than 60mm can be adapted, which makes this distance an excellent choice. You can get cheap medium format lenses, though if you have the budget for this behemoth of a camera and everything that goes with it, why would you want old lenses that are not rehoused for cinema applications?

Which brings us to the kill-joy part, the workflow.

What about workflow?

Codex has released the VaultLab65, almost the size of a grip truck (just kidding):

Codex VaultLab65

The Alexa 65 can record to the following resolutions:

Alexa 65 recording formats

That’s 0.7 TB/s (though in the official specs the data rate is 850 MB/s)!! If you shoot a 90-minute movie with a shooting ratio of 5:1, you’ll need about 20 TB. A feature or documentary will easily be in the hundreds of terabytes, and most likely in the Petabytes. The camera does not record in Prores. Here’s the workflow diagram:

Codex workflow 65

I’ll stop here. Pros will shit in their pants.

Let’s address one reason why this camera is revolutionary, which might not be so obvious. The weight of the Alexa 65 is 10.5 kg – which is almost similar to what the Arricam ST weighs with film loaded. That sounds like a killer deal, but one can rarely film this camera without the accompanying Codex recorder solution – unless you only want 11 minutes of footage for some reason.

What this means is, the solution will not be as heavy as an IMAX system, but will be similar to using a Super35mm film camera with all the reels one has to carry. The advantage of a 11 minutes-at-a-time (like a film magazine!) media card makes this camera shoulder-mount friendly as well:

Alexa 65 Shoulder

Oh, one more thing. The Alexa 65 has a frame rate range of 20-27 fps. This means, most likely, one will shoot 24 fps. More options are possible in future updates. Again, one must be careful what one wishes for. Even if 120p is possible at 6.5K, the data rate will be a cool 3.5 TB/s. This is almost in the realm of science fiction.

A quick comparison of the Arri ALEXA 65 with the Red Epic Dragon and Sony A7s

Why the Sony A7s? Well, it’s the only other ‘large sensor’ that can shoot 4K. On the other hand, the Red Epic Dragon is the only camera that can shoot 6K, but with a Super35mm-sized sensor.

Which makes the Alexa 65 special and unique. You must understand the package here. It’s a medium format 6.5K recording beast, made for one purpose only – to deliver the higest image quality possible. If the dynamic range is greater than 14 stops, and the highlight rendering anywhere near the Alexa XT, this camera is the ultimate cinematographer’s ultimate dream for the ultimate project.

My thoughts on the Arri ALEXA 65 and who it is for

Large scale big budget movies. Mega documentaries. And small format movies like The Master, where the goal is to get the ‘medium format look’. Though the price for this look is going to be too steep for the average die-hard fan.

I’m pretty excited about the camera and its possibilities, though after shooting I would want to go to sleep and let someone else handle the workflow. Question is: how many studios in the world are equipped to handle this beast?

So, what does the future hold? For one, I can bet my bottom dollar that Sony will come out with a similar sensor with an 8K resolution, and maybe Red might too. Though, if the Alexa XT is any indication, neither will trump this beautiful feat of engineering. Just my 200 million cents.

Exclusive Bonus: Download my cheatsheet (with examples) of tried and tested ways to cover a scene or action that will save your skin when your mind goes blank (PDF file optimized for mobiles and tablets).

13 replies on “Thoughts on the Arri ALEXA 65 65mm 6K Camera”

LieMAX Digital lol… IMAX themselves say that 35mm is good for 6,000 lines of resolution (6K) and 70mm film is good for circa 18,000 lines of resolution, thats 18K @ 4:3 AR – squeezing 1.78:1 (16:9) into that Anamorphically (which is roughly what most these IMAX shots are displayed at) results in slightly less lines of ‘output’ resolution, but still a huge amount higher than the Open Gate of the Alexa 65 @ 6K/2.11:1

the IMAX / Alexa hybrid is just the same camera but with IMAX’s own lenses, the above picture does not give a true representation of 70mm film versus 65mm digital, because film captures finer detail than pixels in a sensor the same size as the film in question, therefore you cant just overlap the size of the 65mm digital capture area over the top of 70mm film capture area and say thats the difference, it may well be in physical size…but not in amount of detail captured…

…as someone said already, where years away from coming anywhere near IMAX quality in digital video capture, even then you still need your local cinema to upgrade its projectors to be able to display the native format of the input.. currently we get directors capturing 3-5K worth of resolution, been upscaled by IMAX DMR … for it to only be downscaled to regular HD 2K, my local IMAX Digital uses 2 x 2K projectors, these display over each other to make the image brighter…doesnt make it 4K resolution..its still just 2K…same as the regukar screens!! infact ive seen some people say that their IMAX digital is the same as mine with two 2K projectors for brightness, but the regular screens having 4K!!

thats my 2pence worth lol

You sure about that? You should watch Steve Yedlin’s Resolution Demo. The Alexa 65 stomps IMAX film in terms of resolution. The resolving power of film has been vastly over-stated.

Don’t get me wrong, I still love film, but to claim IMAX is equivalent to 18K digital capture is pure nonsense.

When you think about it, the Sony A7SII is amazing. Obviously not as good as the Alexa 65but in a form factor as small as this, combined with low light, pretty sophisticated tech without issue. Excellent piece on the 65. Thanks for posting this.

I recently watched Sully in IMAX. I have to say I was disappointed. Though may sequences were awesome in the large format, the picture wasn’t quite as big (tall) as IMAX sequences in other films shot with film IMAX cameras, and I could also see pixels (“screen door” in white areas, “jaggies” in areas of fine detail or curves) on the screen. I never saw that in sequences from movies shot with film IMAX cameras. Is this really what the Arri Alexa 65 has to offer? I love the fact that they can do the whole movie in IMAX, but if it’s going to be like that, I almost prefer just parts of the movie in the old film IMAX format.

It could be for many reasons. Poor compression or projection, something wrong in post. As far as resolution is concerned though, IMAX is much larger than 65mm. I loved those dome IMAX documentaries, but we’re still five years (at least) off from any digital camera that might compete with that.

So it seems that the reason I saw the pixels was most likely because the cinema projected the movie using the 2k Christie IMAX projectors, instead of the superior 4k Laser IMAX projectors – even though the screen was a large format 1.43 AR one previously used for film IMAX projection. It wasn’t the camera’s fault.

It’s a shame that theatres downgraded their projection systems like that.

another camera to flood the already swamped arena. snappers have been very happy using the 5d’s or nikon equivalent for the past ten years, yet, tv, is so confused with what format/camera/codex/sensors etc… as the market is so varied and confusing.
exciting it may be but the days of one camera two lenses seems to have gone to bed for good.

I understand what you’re saying but I can’t recall a period with only one camera and two lenses. There were always too many choices.

Yes, I hope so. Apparently the digital IMAX are mostly 2K at prsent which is why the resolution is not that amazing, especially when projected on the full size screen. It could be that cinemas don’t upgrade that quickly as many people don’t notice or care about resolution in cinemas (I’m not sure what percentage of people even know cinemas are nearly all digital!) so long as the image is big and bright.

I’m really looking forward to seeing the images that come out of this. The only thing I wonder about, is where we cannwatch the content; nothing I have seen compares with IMAX film projected on film in a full size IMAX cinema. Even the digital IMAX projector doesn’t get close. Without a matching projector, I wonder if it will be possible to see the full quality of this camera’s image

Comments are closed.