optics correction data, Adobe, Iridient, exiftool ...

I hate the way sub-forums multiplied in post-processing section beyond any reason, so I shall post here

Adobe ACR / LR raw converters are known to either not use optics correction data already embedded in raw files by camera's firmware ( and forcing people to wait , sometimes for a ~year for their own profile to be delivered - like was the case with Sony FE 24-70mm f/2.8 GM II ) OR force such optics correction on users w/o any option in UI to switch it off

So what to do ? one of the options is to use an appropriate Iridient *-Transformer and let it expose optics correction data ( also controlling which correction we do NOT want to use - for example not passing vignetting correction - all that you can setup in Iridient software UI) for example as DNG tags - but it will generate linear DNG - some people don't like it and need non-linear DNG ( for example to use various Adobe's Ai-Enhance tools that will not work with demosaicked DNG ) ...

however we can at the same time generate a non linear DNG file using Adobe DNG converter and force optics correction data revealed by Iridient software to that non linear DNG with exiftool

using something like: exiftool -n -TagsFromFile <dng from iridient> -OpcodeList3 <dng from adobe> -overwrite_original

PS: may be Brian Griffith the man behind Iridient eventually will add an option to generate a non-linear DNG just to let people use optics correction data from raw files in ACR/LR w/o Adobe imposing what we can or can not do w/ what is already available inside raw files.

I wonder why Adobe does not use Sony's embedded profiles for SDC, but they do it for Nikon and Leica.
What do you mean by non-linear DNG? For example, a TIFF can also be converted into a DNG, which is not a linear DNG. Do you mean a non-demosaiced DNG?

a linear DNG is a demosaicked DNG, so a non-linear DNG = a non-demosaicked DNG ... my apologies if using "non-linear" confuses somebody

AFAIK:
A linear DNG must be scene-referred. Not every demosaiced DNG is scene-referred (e.g. when used as a container for TIFF). A demosaiced DNG that is output-referred is not a linear DNG.

In the past, the raw converters from most camera manufacturers have been able to produce a 16 bit linear TIFF or a gamma corrected TIFF and are usually available as soon as a new camera model or a new lens is sold. Is this no longer true for Sony Capture One Express? These software from camera manifacturers have seemed to me to do very well at the de-mosaic step in processing. If the lens is from the same manufacturer as the camera, then they are also likely to do well at distortion correction and chromatic aberration correction, else it is possible to create a LensFun profile which can be used by a variety of software to do distortion correction.

For at least Sony, Canon, and Nikon it seems to me that the software from the camera manufacturer does very well at the de-mosaic step. Is this no longer true for Sony?

If a non-linear TIFF is wanted, why not set the white balance and adjust the gamma curve during the de-mosaic of the raw file? The software from the camera manufacturer seems to me to do very well at creating color from raw and a 16 bit non-linear TIFF will have enough information for later processing.

The "exiftool -TagsFromFile" should I think be used copy from the out of camera raw file to the first file in the processing chain that is able to hold the metadata. I have not been using "-n" with "-TagsFromFile" and I wonder, why is that necessary? Thanks in advance.

What I am writing might not make sense because I have not used any Adobe software for many years and have been using Canon instead of Sony.

thank you but your point ( that linear DNG is a demosaicked DNG + whatever else you want to add, such as absence of any color transforms applied or simply declared by a tag ) is irrelevant to the topic ...

for the purpose of the topic ACR/LR do not let you use Ai-Enhancements for a demosaicked DNG ...

any linear DNG is a demosaicked DNG (with or w/o any extra strings for the purpose of a more formal definition) ...

whether or not any manipulations were done in addition to demosaick is irrelevant ( for practical purposes ) - I can do any further manipulations with DNs in linear DNG w/o leaving a trace in metadata and software further down the line will be clueless if that in fact was a color transform ( as I did not declare that now DNs are coordinates in some formal color space )

My point was supposed to be that a “non-linear” DNG can be either demosaiced or undemosaiced.

you TOTALLY miss the point of the topic - the point of the topic was how people can use optics correction data from raw files (w/o resorting to linear DNGs post software like Iridient Transformers) in cases when ACR/LR do not let you to do this ( Canon's own optics corrections for example) or restrict you ( to using only parts of what is available) of force you to use all optics corrections from raw ( and you do not want to use vignetting correction for example), etc....

I agree that I missed the point. I do not see any point to using any Adobe software. Sorry for the intrusion.

and the sole purpose of the topic - which is dealing ONLY with the (A) actual straight output from ACR/LR/Adobe DNG converter ( to get a "non-linear" DNG from the source raw file ) and (B) actual straight output from Iridient transformers ( to get optics correction data exposed as DNG tags readily available for further manipulations from linear DNG - which is the only output available as of this moment ) and not with anything else.

if you can produce a demosaicked "non-linear" DNG straight from Adobe DNG converter please do share which options to use to achieve that - absent that please open a separate topic about your point related to fully correct definitions of what "linear" or "non-linear" DNG shall be ...

I can sense your frustration in not getting a direct answer to your question, but it seems that the term "non-linear DNG" is not widely understood - at least in my experience.

"Linear DNG" is indeed used to describe partially processed image data, demosaiced but with a linear tone curve.
www.dxo.com/tech-news/linear-dng/
rawpedia.rawtherapee.com/How_to_convert_raw_formats_to_DNG

To my mind "mosaiced / demosaiced" data and "linear / non-linear" tone curve are orthogonal concepts. There are 4 possible combinations.
Raw data from a Bayer sensor is unprocessed, so not demosaiced. It is usually linear although I have encountered sensors intended for industrial applications with a non-linear but piecewise-linear tone curve applied to the output.

I consider that a non-sequitur. This usage is indeed confusing, but you have doubled down on it.

I did wonder if "non-linear DNG" might be used in communities I don't encounter, but the only reference Google found was in a rawdigger discussion, posted by one deejjjaaaa.

"Raw DNG" might be a better term, although it would imply that operations such as noise reduction have not been been applied.

I appreciate that this does not respond to your intended point, but might help reduce off-topic answers in future.