DNG vs Linear DNG

[davidedric]

Hello.

I have been experimenting with a combination of DXo Optics and Lightroom, and I am quite impressed.

I can pass my RAW image to DXo from Lightroom, but what I get back is a "linear" .dng Can anyone enlighten me as to the (practical) difference between regular.dng and the linear version.

Take,

Dave

[xpatUSA]

Hello.

I have been experimenting with a combination of DXo Optics and Lightroom, and I am quite impressed.

I can pass my RAW image to DXo from Lightroom, but what I get back is a "linear" .dng. Can anyone enlighten me as to the (practical) difference between regular.dng and the linear version.

Here y'are, Dave, a piccy is worth a thousand speculations - especially when Eric Chan hisself speaks



I can post the whole page as a link if you like, there might be more context . .

[edit] http://www.barrypearson.co.uk/articles/dng/linear.htm [/edit]

[dje]

Hello.

I have been experimenting with a combination of DXo Optics and Lightroom, and I am quite impressed.

I can pass my RAW image to DXo from Lightroom, but what I get back is a "linear" .dng Can anyone enlighten me as to the (practical) difference between regular.dng and the linear version.

Take,

Dave

Dave this DXO Optics Tutorial may help. In particular, this quote from the tutorial

"If you choose to export your image in DNG format, you will probably perceive a difference between how it is in DxO OpticsPro vs. Lightroom. Also:
If you want to work on light and color in DxOOptics Pro, we recommend that you export your image in TIFF format so as to avoid any surprises in the rendering.
If you prefer doing light and color work in Adobe Lightroom and want to use DxO OpticsPro only for corrections tied to details and geometry, the DNG format will allow you greater flexibility."

The Linear DNG format seems to be a de-mosaiced version of the raw DNG file. ie it has R,G and B values for each pixel rather than one value per pixel. The "linear" part refers to the fact that these R,G and B values have no tonal manipulation applied. Presumably any tonal manipulation you do in DXO will be lost if you export in this fromat.

A bit of experimentation is probably in order !

Dave

[xpatUSA]

This is probably both irrelevant and inapplicable to the question at hand.

A small company (Kalpanika) has produced a command-line program to de-code Sigma X3F files, particularly of interest to later camera owners because support is rare for later raw files.

The default output is Linear DNG, thereby retaining some advantages shown in my earlier post.

However, the EXIF meta-data in the original Sigma X3F raw file is not passed on to the DNG, and if Phil Harvey's ExifToolGUI can't see it, it ain't there, trust me. Maybe just the Kalpaniki converter did that - or maybe there are no tag allocations for EXIF in the linear DNG format.

There are a load of 'IFD' tags filled in but no camera, lens or exposure data at all.

So, if EXIF is important, it could be worth checking what's in the file from DxOoptics.

For me, Linear DNG is a no-go because it crashes RawTherapee 4.2.222 immediately when trying to open.

For what all that's worth . . .

[davidedric]

Thanks, guys.

I have all the information I need - all I have to do is make sense of it. A good holiday project, I think.

Regards,

Dave