Adobe Photoshop CS3 question

[fenger]

Could anyone explain to me what the menu item "Edit->Preferences->File Handling->Prefer Adobe Camera Raw for JPEG Files" does?

Also, what raw format file should we use to archive our raw file pictures? In the original camera specific raw file format?

[MATT]

I'm pretty sure that when you tick that box, the JPG is opened first by AdobeRaw just like a raw file. Giving you control over all the same options to adjust before opening like a raw file.

MATT

[Greg B]

Also, what raw format file should we use to archive our raw file pictures? In the original camera specific raw file format?

Interesting question. I have been experimenting with the Adobe DNG format, which I note gives a significantly smaller file size to the Nikon RAW file,
for example D200 RAW 15Mb, DNG maybe 8Mb.

Obviously a big saving in space, but is anything lost? It would seem that there must be something lost, but I gather Adobe claims no loss.

Does anybody know?

[Oneputt]

For long term archiving Adobe DNG would appear to be the way to go. NEF may not always be supported.

[AndyL]

Fenger,

Check the jpeg in camera raw box and see. It is a handy tool for correcting jpegs.

[fenger]

I'm pretty sure that when you tick that box, the JPG is opened first by AdobeRaw just like a raw file. Giving you control over all the same options to adjust before opening like a raw file.

Yes it does.

What confused me was that when I had that option turned off, PS would still open AdobeRaw when I opened jpg file.

I have figured out what went wrong. I clicked Done instead of Cancel in AdobeRaw. Even I did not make any changes and did not specifically save the image, AdobeRaw would still update the jpg file. The file size increased by a few bytes. The next time I open the file in CS3, it will automatically open AdobeRaw even I have the option turned off.

[fenger]

Obviously a big saving in space, but is anything lost? It would seem that there must be something lost, but I gather Adobe claims no loss.
Does anybody know?

Anyone knows?

If there is no lost of information, I'll start to archive in DNG format.

[DanielA]

Obviously a big saving in space, but is anything lost? It would seem that there must be something lost, but I gather Adobe claims no loss.
Does anybody know?

Anyone knows?

If there is no lost of information, I'll start to archive in DNG format.

Don't quote me, but I was under the impression that the image is demosaiced and placed in the DNG as a flat RGB image. Otherwise every application that wanted to read the DNG would have to understand the particular mosaicing used.

Now this probably doesn't matter. But sometimes the demosaicing algorithms are updated. So today you'll get a better image from the NEF than you would have reading it years ago. I.e. You'll lose that potential upside.


Having said all this. Looking at the spec it appears the mosaicing can be encoded in there, so maybe the data is retained as is. You might have to do some more reading.
Sorry Not much help there.

Daniel

Edit: Ah, it depends on which option you select. From the readme:

Image Conversion Method:

Preserve Raw Image – the image data is stored in the original “mosaic” format, if possible, which maximizes the amount of data preserved. Mosaic image data can be converted to linear data but the reverse is not possible.
Convert to Linear Image – the image data is stored in an interpolated (“demosaiced”) format. This can be useful if a camera’s particular mosaic pattern is not supported by a DNG reader.

[fenger]

The best explanation I can find is explained here http://www.photoshopnews.com/2005/05/23/dng-workflow-part-i/

What I have to decide is whether I should embed my original raw files in the DNG files. From the users' comments below the article, it seem that some people have file corruption issues. Maybe I should not embed the original file and keep both the original and the DNG files.

[Greg B]

The best explanation I can find is explained here http://www.photoshopnews.com/2005/05/23/dng-workflow-part-i/

What I have to decide is whether I should embed my original raw files in the DNG files. From the users' comments below the article, it seem that some people have file corruption issues. Maybe I should not embed the original file and keep both the original and the DNG files.

That is an excellent article, thanks fenger.

I can't really see the point in embedding the original RAW file in the DNG. If you are going to retain the RAW file, I would think you might as well just keep the NEF and the DNG.

However, my main reason for considering DNG is space - the DNG is smaller than the corresponding NEF. If you are going to keep the NEF anyway,
why bother with the DNG?

I know the standardised format argument, but couldn't you just retain the DNG converter to convert files if necessary in the future?

Anyhoo, all fun.

[fenger]

I can't really see the point in embedding the original RAW file in the DNG

Easy file maintenance. One file contains all version. If the raw file is not NEF or CR2, you might want to embed the original.

If you are going to retain the RAW file, I would think you might as well just keep the NEF and the DNG.

If not for the possible corruption of the DNG, I would just keep the DNG with no embedding. Much smaller size.

I know the standardised format argument, but couldn't you just retain the DNG converter to convert files if necessary in the future?

Your DNG converter may not run on your latest version of Windows or whatever OS. You have to find a version of photo editing software which support NEF and can run on your computer. Even so, you have to convert and re-archive everything.

There is one very good reason of using the DNG now. It contains the setting you have used to correct the photo and also generate a thumbnail version of the corrected photo. When you browse the photos in Adobe Bridge, you see the corrected photos. If you want to output, say a file to be used for website, you just open it and output a small jpg for web use. With just the NEF, you just have what was taken with the camera and you may want to go through the correction task again.