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.
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.
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.
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.
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.
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.
