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View Full Version : Applying Rec.709/studioRGB (16-235) in Layout



vncnt
10-12-2012, 12:23 AM
I need to render to Rec.709/studioRGB (16-235) in Layout without re-rendering in NLE.

What whould be the best approach?

RebelHill
10-13-2012, 02:08 AM
the rec 709 preset in the colour space options (except you'll probs wat to chage the display setting back to sRGB, unless u happen to be using a rec709 monitor).

vncnt
10-13-2012, 11:24 AM
When I use the Rec.709 (or RGB) preset the output is full range (0-255), not studioRGB (16-235).

Dexter2999
10-13-2012, 12:53 PM
from the wiki page (here http://en.wikipedia.org/wiki/Rec._709 )


Digital representation

Rec. 709 coding uses "studio-swing" levels where reference black is defined as 8-bit interface code 16 and reference white is defined as 8-bit interface code 235. Interface codes 0 and 255 are used for synchronization, and are prohibited from video data.

vncnt
10-17-2012, 05:50 AM
Does that mean the Lightwave implementation of Rec.709 is incorrectly implemented?

Or should there be an option to choose between 0-255 or 16-235 range?

Dexter2999
10-17-2012, 06:49 AM
No.

In Rec.709, black is 16 and white is 235. That is the range you are talking about.
0 and 255 are sync points. No image information is outside of black and white. You can't "choose" to delete the sync points.

gerardstrada
10-23-2012, 06:53 AM
The luma level adjustment (16-235 range from the original 8-bit range) is required to prepare files for final output for display on HD TV systems. This is made through a codec, or other software, or hardware (if you are already previewing in a HDTV monitor), not for computer graphic systems - where CG work is commonly previewed - and where full 8-bit range is used for this, and where we commonly need generate images in unbounded mode (full floating point). A 16-235 version however may be an option within LW too.

Guess a LUT with those specs could be made in the Academy/ASC LUT format with some specialized tool, just consider that output-referred adjustments in post-processing are necessary for rendered images, but if you need to preview in Rec 709 (16-235) within LW and later bake this preview to save your output images, there are several free options already available.

The simpler one is probably the SG_CCTools (http://www2.informatik.hu-berlin.de/~goetsch/CCTools/). You can use the color space conversion capabilities of the SG_CCFilter or SG_CCNode to convert from your linear color space to Rec. 709 (16-235 version) by using the proper ICC/ICM profiles (think the video legalized Rec 709 profile is shipped with PS or AFX). Just disable LW CS display and set up the filter in Relative Colorimetric:

http://s12.postimage.org/g6dt9bskd/rec709.png
(more info about its installation at the end of this post (http://forums.newtek.com/showthread.php?127209-CYMK-Ouch&p=1241449&viewfull=1#post1241449))

If you are in a sRGB-range monitor, other way could be by using the gamma conversion capabilities of the SG_CCNode or db&b Colour Space (http://www.db-w.com/products/dbwtools/docs) node in DP Image Filter node editor (http://dpont.pagesperso-orange.fr/plugins/nodes/DP_Filter.html). You could try by disabling the LW CS display and setting up the DP Image Filter NE in this way:

http://s7.postimage.org/61hrt0zff/rec709limited1.png

A bit simpler way could be by using DP Curve Filter:

http://s9.postimage.org/5isj4kqtb/rec709limited2.png

Guess a LW color table may be an option too.



Gerardo