NEF Processing

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Originally Posted by DanK

Open a raw file in Lightroom. make a few edits. On your computer, find the raster file your edits are working on (not the image for screen, which both Manfred and I explained is a raster image).

Until then, I am tuning this discussion out.

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It's probably the same file that's used in a pixelbased editor. It's the same file that's parsed to Photoshop.

Doesn't this look strange??

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Your post also explains why the order of edits in LR doesn't matter--something that has been the subject of several threads over the years. The software recomputes every time one adds an edit, and from what I have read, it doesn't apply the edits in the order carried out by the user.

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George

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Originally Posted by george013

Doesn't this look strange??

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Your post also explains why the order of edits in LR doesn't matter--something that has been the subject of several threads over the years. The software recomputes every time one adds an edit, and from what I have read, it doesn't apply the edits in the order carried out by the user

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No.

My take on this is as follows

Common raw editing software like Lightroom or ACR involves two stages. The initial stage is to take the raw data and perform steps such as

Decompression if necessary
White and black point normalisation
Demosaicing for Bayer sensors
White balance
Colour management which uses the camera profile and transforms the raw RGB data into a recognised color space.

These initial steps lead to the production of a set of colour managed RGB data for the image.

With the second stage of the process, further editing functionality is then based on modifying this RGB data in a parametric fashion.

There should be no need to redo the basic steps of the first stage every time an edit is made in the one session (unless the WB or Camera profile selection is changed), but rather the RGB data is just updated. Of course eVery time a new session is started, the whole process must be repeated.


Something to think about!

Dave

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Originally Posted by dje

Of course every time a new session is started, the whole process must be repeated.


Something to think about!

Dave

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It depends what you mean by session....:) In the Library Module you are only looking at previews which are held as part of the catalog. You can choose the quality of the previews in the settings. It is not until you go to one of the modules i.e. Develop Module that the file maybe opened.

Here is a link to a fairly good explanation of the options.

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Originally Posted by pnodrog

It depends what you mean by session....:) In the Library Module you are only looking at previews which are held as part of the catalog. You can choose the quality of the previews in the settings. It is not until you go to one of the modules i.e. Develop Module that the file maybe opened.

Here is a link to a fairly good explanation of the options.

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Thanks for the link Paul. It seems to give a good summary of how LR manages previews. It's surprisingly complex, glad I don't use the software!:) I think Bridge does previews a bit differently but I've never bothered too much with the detail.

My initial comments weren't really relating to previews but rather to full development mode for a raw image. I was also speaking generally rather than to a particular software package. I dare say they are all a bit different.

Dave

That's the way I figured it out. With the addition that when rebuilding that raster image the sequence won't be changed. Exactly in the way I did it. Every operation on that raster image is done on the situation of that moment. The importance of a sequence discussed here and else is not undone.

Another thing is that a parametric editor doesn't change the source file. What is that source file? In the discussion here before the raster image was assumed to be the source file. It isn't. It's the disk file, the nef, jpg tiff or whatever. But they are never changed during editing. It's the extraction of that file in memory, the raster image in memory that's changed. Only when saving the original is getting involved again. A non-paramatric editor will overwrite it. A parametric editor will add a sidecar file, or include it in the source file as CaptureNx2 does. I believe it's than when the Save and Save As changed in Save and Export.

I still think that simple diagram is correct.

George

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It's probably the same file that's used in a pixelbased editor. It's the same file that's parsed to Photoshop.

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"Probably?" You didn't look, did you, George? If you look in the directory space where the files are, you will find ONLY the raw file and the xml file (assuming you write the metadata to a sidecar file). There is a preview, of course, but that is in an entirely different location. If edit the file in photoshop, I believe LR then has to create a scratch file, but it is in a photoshop temporary directory. It doesn't show up in the directory LR is using until you save it from photoshop.

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Every operation on that raster image is done on the situation of that moment. The importance of a sequence discussed here and else is not undone.

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If you search on this site, you will find threads showing that this is simply wrong for Lightoom. In a discussion about the importance of sequence for noise reduction and sharpening in a pixel-based editor, I posted images showing that it makes zero difference in Lightroom. If I recall correctly, someone then posted a link to an explanation by an Adobe engineer, confirming that sequence doesn't matter.

It's a shame that you are being so stubborn.

Now I really am going to bow out. There is nothing to be gained by discussing this further.

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Originally Posted by DanK

"Probably?" You didn't look, did you, George? If you look in the directory space where the files are, you will find ONLY the raw file and the xml file (assuming you write the metadata to a sidecar file). There is a preview, of course, but that is in an entirely different location. If edit the file in photoshop, I believe LR then has to create a scratch file, but it is in a photoshop temporary directory. It doesn't show up in the directory LR is using until you save it from photoshop.

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You won't find it anywhere. It's not a disk file but a memory file. See my diagram:). A peace of memory that's assigned to the program to contain that image. When you use a plugin like the Nik collection the address of that file is passed to the plugin so it can work on it. On that raster image. In programming language it's "passing by reference"

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If you search on this site, you will find threads showing that this is simply wrong for Lightoom. In a discussion about the importance of sequence for noise reduction and sharpening in a pixel-based editor, I posted images showing that it makes zero difference in Lightroom. If I recall correctly, someone then posted a link to an explanation by an Adobe engineer, confirming that sequence doesn't matter.

It's a shame that you are being so stubborn.

Now I really am going to bow out. There is nothing to be gained by discussing this further.

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If you search on this site you'll see me too.:(
Off course sequence is important. From your former post

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Your post also explains why the order of edits in LR doesn't matter--something that has been the subject of several threads over the years. The software recomputes every time one adds an edit, and from what I have read, it doesn't apply the edits in the order carried out by the user.

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Recomputing in what sequence?
And further. I do a correction with levels, sharpening, blurr,saturisation. And the sequence doesn't make any difference???? Do a search on this site.;)

George

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Originally Posted by george013

And further. I do a correction with levels, sharpening, blurr,saturisation. And the sequence doesn't make any difference????

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No.