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[Michael Borenstein]

Dan,

Thank you for the update.

Regards
Mike

[Torrance]

Looking forward to this option.  Just picked up my first Gemini. 

Robert Torrance

[robstiff]

Getting ARRI RAW out of the Alexa for 2880x1620 footage is an exciting option!

Does the Gemini have the ability for custom framing lines in its monitor?

[Dan Keaton]

Dear Rob,

At this time, we have two built in framing lines.

It is our goal to allow custom framing lines, but this is not yet in our firmware.

[Dan Keaton]

Dear Friends,

In the first post in this thread, Huaza, reported that we, Convergent Design, stated that there is no advantage to recording ARRIRAW over ProRes 4:4:4:4.

I have been researching this topic carefully.

At this time, we definitely feel that there is a quality advantage to recording ARRIRAW.

We are preparing a document that discusses this in detail, but we want to finish it, and send it to ARRI for review before we post it.

[Thomas Wright]

Brilliant.

I don't know too much about MTF and all that but if there were a way of explaining things in imaginable terms like: Shooting arriraw resolves x many line pairs per millimetre when written to film by a 2k arrilaser whereas y many linepairs when recorded prores 4X4 through the same workflow.

Does that make sense?

[Sarah Priestnall]

I think the fact that more than 50 feature films were shot using ARRIRAW with Codex recorders last year indicates that many people agree that there is a difference, including cinematographers like Roger Deakins ASC, Bob Richardson ASC and Matty Libatique ASC.

Sarah Priestnall

VP Market Development
Codex Digital

http://www.imdb.com/company/co0294826/

[DITDANE]

Uncompressed is a higher ideal. 97% of Projects shot for TV (HBO included) are budgeted for a compressed workflow.

9.1GB/hr vs 1.9GB per hour is a huge factor. Now you ask a DP if he'd rather have uncompressed workflow for better color accuracy and finer detail or more lenses/lighting. Guess who wins:)

I look forward to seeing ARRIRAW on the Gemini. Now will it allow for 60fps or max out at 30fps?

[Dan Keaton]

Dear DitDane,

We may bring out our ARRIRAW option with a limit of 30 frames a second.

If we do, then we plan to have 60 frames per second in around 30 days.

Or, if we delay bringing out our ARRIRAW option, then it will come out with 60 frames per second support.

[Jumperjack]

Dear Dan Keaton,

You are making our mouths water.

Jumperjack

[robstiff]

Getting 2880x1620 ARRI RAW footage out of the Alexa at a very low cost makes for an exciting option!

We shoot with the SxS in ProRes444 getting about 14 minutes @ 32GB used (a full 32GB SxS Card).

What is the storage size for 14 minutes of ARRI RAW?

[Dan Keaton]

Dear Rob,

Here is lot more information than your requested,
but I feel that you may find this interesting.

Since a higher quality image can be recorded using ARRIRAW, in 12-bit log,
versus HD, 1920 x 1080 in 10-bit (log or regular),
one would expect the file size to be larger in ARRIRAW, than when recording HD.

However, recording the individual photosites using 12-bits is actually more efficient than recording in the pixels in HD (1920 x 1080) at 10-bits.

In the ARRI ALEXA, for the 16 x 9 sensor, there are 2880 horizontal photosites
and 1620 vertical photosites.

Here are the calculations, for recording 4:4:4 and 24 frames per second, to obtain the data rate per second.

(Some file overhead is ignored in these calculations for simplicity and audio is not included in these calculations.)

For ARRIRAW:

2880 (horizontal photosites)
times 1620 (vertical photosites)
times 12 bits per photosites
divided by 8 bits per byte
times 24 frames per second
equals
167,961,600 Bytes per second
or 167.9616 Megabytes per second. (using a Megabyte as 1000 x 1000 bytes)

Since Hard Disk Drives are usually listed in Gigabytes, but manufacturers almost always use a Gigabyte as 1000 x 1000 x 1000 as oppposed to using 1024 x 1024 x 1024,  I will use Gigabyte as 1000 x 1000 x 1000 to make it easy to see if a given amount of recording time will fit on a Hard Disk Drive or Solid State Drive.

167.9616 Megabytes x 60 seconds/minute = 10,077.7 Megabytes/second
This is 10.0777 Gigabytes per second

For 14 minutes, one needs 141.08774 Gigabytes of storage.

The Gemini 4:4:4 supports both 256 GB and 512 GB SSD's.
And there are two SSD slots.

The Gemini 4:4:4 automatically spans from one SSD to the next.

So, with two 512 GB SSD's, one obtains approximately 101 minutes of recording time.
This ignores the space used for recording the audio.

So, one can record from the ARRI ALEXA, in the ultimate image quality, 12-Bit Log, ARRIRAW, recording each and every photosite, for well over 90 minutes continuously, uninterrupted using two 512 GB SSD's.

I hope this helps.

[robstiff]

Thanks. That's helps a lot.

I believe the HD recording of the Alexa on SxS cards using ProRes444 is 1920x1080 12-Bit for Log-C.

A difference might be seem on a 2K monitor/projector.

Going down from ARRI RAW 2880x1620 to 2048x1080
vs.
Going up from HD1920x1080 to 2048x1080

or maybe not? would be a great test for some side by side frames grabs/still to compare?

Can you post some debayered images from your ARRI RAW test from the Gemini?

[Dan Keaton]

Dear Rob,

Here are ARRI's words:

ARRIRAW is the best format for 2K delivery, the best quality for VFX, and the best option for archiving.

Here is a quote from an ARRI Document:

“When shooting for a 2K post workflow for example, recording ARRIRAW at 2880 x 1620 pixels and down-converting in post to a 2K image shows visibly better resolution than shooting in 1920 x 1080 HD and up-converting to 2K.

This resolution difference is even more pronounced when special effects are involved:
the ARRIRAW files can be reconstructed to a 2880 x 1620 full color image for special effects, and only be down-converted to 2K after the effects have been applied.” 

We are in the process of adding images to the document that we are preparing.

[robstiff]

Very amazing!

With the Gemini, can it sync with the record button on the Alexa or an external run/stop
for recording? Does the ARRI RAW use the same time code for simultaneous recording the
the SxS Cards? It might be great to record a small proxy size file to the SxS, do a laptop edit with
the proxy and later conform an edit decision list to the larger 2880x1620 footage, etc....