Luminous Landscape Forum

Raw & Post Processing, Printing => Adobe Lightroom Q&A => Topic started by: ErikKaffehr on June 07, 2012, 03:31:21 am

Title: Achieving scene oriented rendition
Post by: ErikKaffehr on June 07, 2012, 03:31:21 am
Hi,

I'd like to find out the best way to get scene referred rendering in LR. I need it mostly for testing, but it may also come handy for reproductions.

Best regards
Erik
Title: Re: Achieving scene oriented rendition
Post by: John R Smith on June 07, 2012, 08:28:27 am
Erik

Could you expand a little on exactly what you mean by "scene referred rendering" ? I have to confess I am unfamiliar with the term.

John
Title: Re: Achieving scene oriented rendition
Post by: Simon Garrett on June 07, 2012, 09:49:00 am
John, see for example:
http://www.color.org/scene-referred.xalter (http://www.color.org/scene-referred.xalter)

Erik, I've never used scene-referred rendering, but could you use the profiles in the color.org link above for soft-proofing in LR?  Obviously, you can't alter the working space in LR.  
Title: Re: Achieving scene oriented rendition
Post by: John R Smith on June 07, 2012, 09:55:18 am
John, see for example:
http://www.color.org/scene-referred.xalter (http://www.color.org/scene-referred.xalter)

Erik, I've never used scene-referred rendering, but could you use the profiles in the color.org link above for soft-proofing in LR?  Obviously, you can't alter the working space in LR.  

Thanks Simon.

J
Title: Re: Achieving scene oriented rendition
Post by: Slobodan Blagojevic on June 07, 2012, 10:47:55 am
John, see for example:
http://www.color.org/scene-referred.xalter (http://www.color.org/scene-referred.xalter)...

Sorry, but the linked text is in Greek.

English, please!
Title: Re: Achieving scene oriented rendition
Post by: bjanes on June 07, 2012, 11:05:16 am
Hi,

I'd like to find out the best way to get scene referred rendering in LR. I need it mostly for testing, but it may also come handy for reproductions.

The method (http://www.color.org/scene-referred.xalter) suggested by the ICC works, but only with PV2010. You would have to export the file as 16 bits per pixel with the Linear RIMM profile (assuming that is possible with LR). It is not easy to obtain scene referred data with PV2012.

Regards,

Bill
Title: Re: Achieving scene oriented rendition
Post by: kencameron on June 08, 2012, 03:17:16 am
Sorry, but the linked text is in Greek.

A little harsh, I would say -  the linked text seems to me to be quite well written and easy to follow - and my Greek is no good at all, as I have needed a translator to follow more than one LuLa post.
Title: Re: Achieving scene oriented rendition
Post by: Steve House on June 08, 2012, 06:13:19 am
Maybe I'm just naive but it sounds like a convoluted and technical way to describe a process that is basically what you're doing when you shoot to a raw file with a colour reference card included in the scene.  As I read it, the article defines a scene-referenced rendering as being a file where the various colours in a scene are described in the output file based on their differences from a known colour included in the scene itself rather than referencing some standard base colour.  Isn't that what you're actually doing when you shoot a Color Checker included in your scene and create a profile based on it?
Title: Re: Achieving scene oriented rendition
Post by: sandymc on June 08, 2012, 07:33:36 am
I'd like to find out the best way to get scene referred rendering in LR. I need it mostly for testing, but it may also come handy for reproductions.

That depends  ;D

In brief:

In the earliest versions of LR, the only difference between scene referred and output referred rendering was the tone curve, and you could zero that in the controls.

In later versions or LR, up to version 3, there is an added complication in the shape of the huesatmaps and look tables in camera profiles. Depending on what you're trying to achieve and how exactly you define scene referred, you might want to strip those out. That might require a custom camera profile.

In LR version 4, it's not clear - Eric Chan has hinted that there are changes in this area, but Adobe have not yet published specs for the new DNG version, which would also have specs for the new camera profiles in it. Eric's probably the only person that could give a clear answer.

Sandy



Title: Re: Achieving scene oriented rendition
Post by: bjanes on June 08, 2012, 08:51:21 am
Maybe I'm just naive but it sounds like a convoluted and technical way to describe a process that is basically what you're doing when you shoot to a raw file with a colour reference card included in the scene.  As I read it, the article defines a scene-referenced rendering as being a file where the various colours in a scene are described in the output file based on their differences from a known colour included in the scene itself rather than referencing some standard base colour.  Isn't that what you're actually doing when you shoot a Color Checker included in your scene and create a profile based on it?

This article (http://wwwimages.adobe.com/www.adobe.com/products/photoshop/family/prophotographer/pdfs/pscs3_renderprint.pdf) by Karl Lang discusses scene referred and output referred images in some detail and may be helpful. The main thrust of the article has to do with tone mapping in which the luminances of the scene are mapped to what can be reproduced by the output device. Remapping of out of gamut color may also be needed, but this is not discussed in the article.

The color checker is mainly concerned with color as the gray scale patches are quite limited.

Regards,

Bill
Title: Re: Achieving scene oriented rendition
Post by: Steve House on June 08, 2012, 12:51:28 pm
And in other than scientific research where color rendering might be crucial data, jus what practical difference does it make?  When I make a photograph I'm interested in what looks pleasing and don't really care if it is an exact match to the original scene.
Title: Re: Achieving scene oriented rendition
Post by: Peter Stacey on June 08, 2012, 01:32:36 pm
And in other than scientific research where color rendering might be crucial data, jus what practical difference does it make?  When I make a photograph I'm interested in what looks pleasing and don't really care if it is an exact match to the original scene.

1. Commercial clients (eg. Ferrari red, etc.)
2. Digital reproduction work (eg. recording of artworks, etc.)

I'm sure there are other examples also.
Title: Re: Achieving scene oriented rendition
Post by: John R Smith on June 08, 2012, 01:33:59 pm
And in other than scientific research where color rendering might be crucial data, jus what practical difference does it make?  When I make a photograph I'm interested in what looks pleasing and don't really care if it is an exact match to the original scene.

Steve

It's needed when copying artwork. I often run up against these problems when I photograph my wife's paintings, and she needs prints which are as exact a colour match as possible. Same thing applies to catalogue work for fabrics, I would imagine. What I have done up to now is put a colour checker in the first frame, and try to calibrate to that.

John
Title: Re: Achieving scene oriented rendition
Post by: Steve House on June 11, 2012, 06:33:16 am
Yep, I can see it being needed in reproduction work and advertising as Peter also points out. In the case of your wife's artwork, even more accurate than a color checker in the first frame would be to hold up the actual work being copied first alongside the monitor and then side by side with a trial print.