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Avid - Alexa, RED, and LUT question.

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andrew thompson
Avid - Alexa, RED, and LUT question.
on Jul 29, 2012 at 12:58:07 pm

We are setting up a project in which we're skipping the post house for dailies processing and handling them in our cutting room. We're shooting on Arri Alexa and here is my question; Is there a way to preserve or apply a LUT to that footage in Media Composer?

I ask because of my recent experience on a small project working with RED footage. The R3D files linked in Media Composer via AMA and we did not have to jump through any hoops to retain good looking color. Unfortunately I do not know exactly why this was the case. I don't think the footage was shot Rec709 and we did not import or apply a LUT in the Avid - It just looked good. From what I've read over the past few days this will not be the case with our Alexa footage shot LogC; It will be flat and grey.

Any input will be greatly appreciated - Thanks in advance!


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Michael Hancock
Re: Avid - Alexa, RED, and LUT question.
on Jul 29, 2012 at 1:36:57 pm

Job ter Burg has a great post about this here:

http://forums.creativecow.net/thread/45/884148

----------------
Michael Hancock
Editor


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Michael Phillips
Re: Avid - Alexa, RED, and LUT question.
on Jul 29, 2012 at 6:38:03 pm

Just make sure you settle on how you want to interpret the REEL info - you can use what is embedded (8 characters) or the entire filename. This is set up in Resolve on the configuration page. If you start with embedded, and then choose later to relink via AMA to the "un-lUT'd" files for conform and color correction it may not work due to differences in REEL ID assignment. So make sure you decide how you want to finish and master and work backwards from there.

Michael

Michael Phillips


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Michael Phillips
Re: Avid - Alexa, RED, and LUT question.
on Jul 29, 2012 at 6:40:31 pm

And the reason it worked for RED R3D is that Media Composer supports the RMD file, RED's version of LUT in the sense that it contains all the color metadata that gets applied to the RAW image. This is done via the RED SDK that is part of the R3D AMA plug-in. Media Composer does not yet have a generic LUT support for different camera formats at this time.

Michael

Michael Phillips


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andrew thompson
Re: Avid - Alexa, RED, and LUT question.
on Jul 30, 2012 at 1:09:53 am

Thanks for this very valuable and helpful information - It's much appreciated!


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Oliver Peters
Re: Avid - Alexa, RED, and LUT question.
on Jul 30, 2012 at 1:26:05 am

Hi,

There are a number of ways to deal with this. You can convert in Media Composer or convert externally for editorial. To apply LUTs, you can use SpeedGrade, Resolve, Redcine-X Pro (RED only) or FCP "legacy". My own recipe would be this:

RED - use Redcine-X Pro to convert file
ALEXA - use FCP 7 to apply a LUT filter to source clips and then batch export (renders on export) edit-ready files

I've blogged a fair bit about ALEXA workflows. Info here:

http://digitalfilms.wordpress.com/2010/11/04/arri-alexa-post-part-1/
http://digitalfilms.wordpress.com/2010/11/12/arri-alexa-post-part-2/
http://digitalfilms.wordpress.com/2010/11/18/arri-alexa-post-part-3/
http://digitalfilms.wordpress.com/2011/05/21/arri-alexa-post-part-4/
http://digitalfilms.wordpress.com/2011/05/27/arri-alexa-post-part-5/

Cheers,
Oliver

Oliver Peters Post Production Services, LLC
Orlando, FL
http://www.oliverpeters.com


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andrew thompson
Re: Avid - Alexa, RED, and LUT question.
on Jul 30, 2012 at 1:42:36 am

Hi Oliver,

Thanks for the links to your blog. Before it slips away I wanted to ask about another method we came across. Are you familiar with either of these devices; Sound Devices PIX 240 or an AJA Ki Pro Mini? From what I understand they can attach as 'camera sidecars' that simultaneously record REC709 and LogC. Is that correct? If so, can we edit with REC709 and make EDL's from Media Composer that reference the LogC clips?


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Michael Phillips
Re: Avid - Alexa, RED, and LUT question.
on Jul 30, 2012 at 3:37:58 am

That is certainly a solution to consider. Since the HD-SDI uses a REC.709 LUT for monitoring, then it is already applied when recording to DNxHD in the recorder. It also eliminates the transcode step as it happens in real time during the recording process.

Michael

Michael Phillips


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andrew thompson
Re: Avid - Alexa, RED, and LUT question.
on Jul 30, 2012 at 4:03:33 am

Michael, do you know if there is any way we can double check that the LogC material and the Rec709 are mirrored exactly? Are there any scenarios that include a total meltdown we when go to do the DI when using one of those camera components?


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Michael Phillips
Re: Avid - Alexa, RED, and LUT question.
on Jul 30, 2012 at 4:15:28 am

I've only done workflow conform verification with the PIX240 and R3D files - I have yet to get sample files for PIX and Arri - the one step you need to absolutely do is conform the timecode match with a quick test on-set. The PIX240 allows you to enter an offset to make sure it matches for whatever delays might be introduced from sensor to LUT over HD-SDI. So while the first frame of recorder file may not be the same (~1-3 frames), the timecode of the first frame of the DNxHD proxy should be the same frame in the Arri/RED file (for example, the clap frame).

I also don't know for Arri whether it sends the 8 character Reel_Name or the entire Filename - either way, as long as you conform system works with either one, then you're good.

Michael

Michael Phillips


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andrew thompson
Re: Avid - Alexa, RED, and LUT question.
on Jul 30, 2012 at 4:29:45 am

I get what you're saying about the REEL ID but I'd like to clarify what I think i'm reading about matching timecodes.

We would run a camera test and check to see if sync points on both LogC and Rec709 footage have matching time code. If they don't then we would apply an offset on the box.

Is that correct?


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dermot shane
Re: Avid - Alexa, RED, and LUT question.
on Jul 30, 2012 at 5:03:23 am

ummmm... maybe a LUT in your monitor, or in a box like the BMD HDlinkPro before your monitor?

very simple & elegant answer really...

d


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Oliver Peters
Re: Avid - Alexa, RED, and LUT question.
on Jul 30, 2012 at 1:55:32 pm

[Michael Phillips] "I also don't know for Arri whether it sends the 8 character Reel_Name or the entire Filename"

The ALEXA assigns a clip name like this: A001C001_120613_R259.mov
The reel ID it embeds for this is: A001R259
This reel ID corresponds to the card ID.

To my knowledge, this doesn't come across when you record to a KiPro or PIX240. The operator has to manually assign reel and clip numbers on those devices. I'm not 100% sure about the operational particulars of each device. As I recall, on the full KiPro, which records to a hard drive, the reel ID assigned to clips is based on the hard drive name, usually 001. Since the hard drive can hold more media than the SxS cards, you could have more clips on the hard drive than on any given card. Therefore, not only would the reel ID be different, but the relationship of media between cards and hard drives would be completely different. This, of course, varies when you use the KiPro Mini, which records to CF cards.

Clearly by going this route, you put a lot of burden on the production crew, camera assistants, DIT and/or data wrangler to get it right. That's a recipe for disaster if the production (and post) is constrained for time and budget.

- Oliver

Oliver Peters Post Production Services, LLC
Orlando, FL
http://www.oliverpeters.com


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Oliver Peters
Re: Avid - Alexa, RED, and LUT question.
on Jul 30, 2012 at 12:09:30 pm

"Before it slips away I wanted to ask about another method we came across. Are you familiar with either of these devices; Sound Devices PIX 240 or an AJA Ki Pro Mini?"

Yes, and I've had mixed results. I do not advocate using these (outside of back-up or video assist) UNLESS they are the primary recorder. The on-board cards would be back-up. With Alexa you can record Log-C to the SxS cards and REC709 out via SDI to an external recorder. The devices can be set-up to be triggered by TC, so the recording will USUALLY match the start/stops to the cards and match TC. Sometimes there is a several frame differences in start/stop/durations and sometimes the actual a/v will be 1 frame different than the cards, thanks to internal processing. Several problems, though:

Clips names will not match and reel IDs will not match.
Sometimes clips are missed.
Sometimes the recorder hiccups in the middle of long takes and you'll miss part of the recording or get two clips.

Some cameras do not put out the same signal via SDI. The Alexa will record and output 23.98 simultaneously. Not sure about RED. The C300 OTOH will record 23.98 onboard but only put out 29.97 with 3:2 via SDI. In a recent production we used a PIX240 as the prime recorder with a C300. It worked well, but I had to rely on the PIX240's internal processing to correctly remove 3:2 and get back to a proper 23.98 file. In that case, the PIX240 was the main recording and the camera cards were only back-up.

You will be MUCH happier if editorial has complete control of prepping the media.

Oliver

Oliver Peters Post Production Services, LLC
Orlando, FL
http://www.oliverpeters.com


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Michael Phillips
Re: Avid - Alexa, RED, and LUT question.
on Jul 30, 2012 at 12:24:49 pm

I agree with Oliver's points, and everything needs to be tested. As I mentioned, I have only seen files from the RED camera and the filenames do match, but I do not believe the same works for Arri Alexa at this time. The Arri needs to send that info down the HD-SDI as part of a future camera firmware update.

But there is still nothing better than working with the original camera originals in order to know that those files are all correct, not corrupt with a card transfer, etc. Same as the film days - the camera tap was nice, but it wasn't what you were shooting. :) Digital certainly makes that closer, but knowing the original files work, and play all the way through is comforting.

Michael

Michael Phillips


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andrew thompson
Re: Avid - Alexa, RED, and LUT question.
on Jul 30, 2012 at 1:25:15 pm

Thank you both for your time and input. Hopefully I can repay the generosity someday.


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andrew thompson
Re: Avid - Alexa, RED, and LUT question.
on Jul 31, 2012 at 12:16:20 am

In Resolve(lite) the framerate inside RENDER PROPERTIES is locked in to 60 FPS. Is there a way to render at 24?


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Glenn Sakatch
Re: Avid - Alexa, RED, and LUT question.
on Aug 2, 2012 at 7:09:59 pm

Did you set up a 24 frame project before you started? Resolve can't change its project frame rate after the fact. Your initial setup needs to be set correctly (according to what you need it to be)

Glenn


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