Thursday, November 28, 2013

[Avid-L2] RE: RE: ARRI Alexa LCC Look Files quagmire

 

Are you sure of that? How are they recording the actual media?


It is my understanding that if the recording is going to the onboard cards as ProRes or DNxHD, it is one or the other. The LCC is loaded as a REC 709 LUT and this means on-board recordings are only REC 709. AFAIK, there is no such thing as Log-C with the LCC LUT. It's still a REC 709 recording, but I could be wrong. The LCC is simply a less extreme Log-C-to-Rec709 LUT. You might want to poke around on ARRI's forums and see what they say.


http://forum.arridigital.com/forum/


The Alexa allows you to record Log-C to the cards and a REC 709 feed out the SDI port to an external recorder, as well as the other way around. So you might want to verify if recorded media actually exists that is truly Log-C. Of course, if the master files are raw, none of this matters.


I haven't worked with ALEs for Alexa in MC7 so I can't answer that question.


- Oliver 



---In Avid-L2@yahoogroups.com, <ph@...> wrote:

Finally had a conversation with the DoP and the DiT - why didn't it happen beforehand remains a mystery. Basically, they are still using Log-C but with a custom LUT (the LCC provided by Arri), so the workflow follows pretty much all the white papers out there.


One new weird thing popped up though: most of the ALE from the camera won't import in MC7 when my assistant imports them (with the Merge options in the ShotLog settings). Checked the ones from the first day, and they had no Source or Tape column.  Changed one of the headings to Tape and it worked, but the ones from the following day won't work. I'm waiting to receive them by email to double-check.


Anything we should be wary of when it comes to import the ALEs?



---In avid-l2@yahoogroups.com, <oliverpeters@...> wrote:

As long as they are consistent and stay with the LCC "look", you don't need to do anything. No other LUTs required. Simply color correct if you want to, like normal. It's simply a low contrast profile.


There is no secret to any of this. Even is they had shot Log-C, it is simply a gamma profile. You are still working with it in Rec 709 color space if you in an NLE. A Log-C-to-Rec-709 LUT is nothing other than an inverse curve to offset the log curve.


- Oliver 



---In Avid-L2@yahoogroups.com, <ph@...> wrote:

Starting a project shot on Alexa. There was a slight communication problem with the camera department but it looks that they're not shooting with a Log-C but with with Look Files and LCC. From what I understand, it means the camera is recording directly into REC709.


The DiT is supposed to give us MXF files he creates with Resolve -in DNxHD36 (or DNxHD115 if it's worth the bigger files)- for offline editing. We read most of the white papers out there, and whilst there's a lot of info on how to get it right under normal circumstances and some good step-by-step litterature, it's always about Alexa Log-C to REC709. So we're a bit concerned because when we asked for Ycrbr REC709, he said he can't do anything else than RGB. It's rather confusing because LCC seems to be already REC709. If someone can shed some light on that workflow, it would be great because we don't even know what project settings should be used - apart from 1080p/24fps - the color space we should use is a mystery.


Sorry for those who also saw that post on the Avid forum. Figured there might be more film experts here!

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