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Archive 2009 · Are DNG's "baked" negatives?

R_K_A
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p.1 #1 · Are DNG's "baked" negatives?

I've been googling for an hour trying to answer a seemingly simple question. I'm trying to determine if I can modify a CR2 file in ACR and export a "baked" DNG from which a client or other person can not reverse engineer (now or in the future) to find my edits to the raw file or get back to the original start state of the raw file before I manipulated it. I know I can save it as a TIFF and that would accomplish what I want. It's more a question of what's inside the DNG file.

Oct 28, 2009 at 08:53 PM

colinm
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p.1 #2 · Are DNG's "baked" negatives?

If you hand them a DNG, they can do whatever they want with it; it's just a well-documented raw format.

Oct 28, 2009 at 09:12 PM

R_K_A
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p.1 #3 · Are DNG's "baked" negatives?

Gracias!

Oct 28, 2009 at 09:13 PM

cgardner
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p.1 #4 · Are DNG's "baked" negatives?

Just give them a high quality JPG. JPG files saved at high quality levels don't have much if any perceptible loss in quality. The savings in size comes from the way the encoding is done. Open a file in Lab mode and look at the three channels individually. Note how the L carries all the detail and the other two are relatively flat and shapeless? That's similar to the way JPGs are encoded. Splitting out the color that way makes it more compressible without apparent loss in IQ. Save a file as a .PSD, DNG, TIFF and JPG then make an 8 x 10 prints from each file and compare IQ.

Oct 28, 2009 at 09:18 PM

AdrianRogers
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p.1 #5 · Are DNG's "baked" negatives?

cgardner wrote:
Save a file as a .PSD, DNG, TIFF and JPG then make an 8 x 10 prints from each file and compare IQ.

Heck print them out even bigger, it's still hard once you're at an acceptable viewing distance. A jpg will fall apart if you're re-editing and resaving it, but if it's the final output from a RAW file it's more than acceptable IMO.

Oct 28, 2009 at 10:48 PM

R_K_A
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p.1 #6 · Are DNG's "baked" negatives?

AdrianRogers wrote:
A jpg will fall apart if you're re-editing and resaving it, but if it's the final output from a RAW file it's more than acceptable IMO.

And that is precisely why I'm looking into something other than a jpeg.

Oct 28, 2009 at 11:30 PM

cgardner
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p.1 #7 · Are DNG's "baked" negatives?

AdrianRogers wrote:
A jpg will fall apart if you're re-editing and resaving it, but if it's the final output from a RAW file it's more than acceptable IMO.

Only if you edit, save, edit save, edit save... ad nauseum

If you start with the master JPG for all the edits the worst case is third generation:

PSD > JPG > Resave

What looks acceptable is a subjective value judgement. Don't speculate and pull facts out of your ear, or make decisions based on what someone else finds acceptable do some actual testing and ocular inspection.

Start with a L12 JPG and save, open and resave about 6 times as L12 jpgs the same size and compare. Do same size re-saves to eliminate the variables do to resizing that would occur in any case.

Oct 29, 2009 at 03:07 AM

AdrianRogers
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p.1 #8 · Are DNG's "baked" negatives?

cgardner wrote:
AdrianRogers wrote:
A jpg will fall apart if you're re-editing and resaving it, but if it's the final output from a RAW file it's more than acceptable IMO.

Only if you edit, save, edit save, edit save... ad nauseum

Entirely depends how much you intend on editing it. A JPG doesn't have the same processing leeway as a RAW file.

Oct 29, 2009 at 01:00 PM

R_K_A
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p.1 #9 · Are DNG's "baked" negatives?

AdrianRogers wrote:
Entirely depends how much you intend on editing it. A JPG doesn't have the same processing leeway as a RAW file.

Precisely. Thank you.

Oct 29, 2009 at 02:52 PM

cgardner
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p.1 #10 · Are DNG's "baked" negatives?

AdrianRogers wrote:
cgardner wrote:
AdrianRogers wrote:
A jpg will fall apart if you're re-editing and resaving it, but if it's the final output from a RAW file it's more than acceptable IMO.

Only if you edit, save, edit save, edit save... ad nauseum

Entirely depends how much you intend on editing it. A JPG doesn't have the same processing leeway as a RAW file.

True, but the context of this discussion is a finished file sent to a publication.

If the photo started in RAW and was corrected for contrast, exposure, WB, etc. the most the editor getting the JPG would probably do is crop / resize.

If you have any qualms about JPG just give them TIFF and let them deal with the file sizes.

Chuck

Oct 29, 2009 at 05:50 PM

R_K_A
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p.1 #11 · Are DNG's "baked" negatives?

In general, you are correct, however in my particular case, the intent is to provide a file that allows maximum flexibility to further edit, if they so choose. I don't have any interest in delivering the RAW files to achieve that requirement so I'm looking at the alternatives.

Oct 29, 2009 at 09:08 PM


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