Reconverting psd to dng

[BhSussman]

Hello

I'm triying to copy my historical lightroom folders to an offline external drive as a backup. Some of my lightroom folders have edited files in psd format that I copied back into lightroom. To simplify things I've begun to copy ALL files as DNGs (in order to keep my final edits), even psd files. Disregarding the efficacy (or lack thereof) I'd like to know if converting psd files (mostly 16 bit) to dng files significantly damages the quality of the file.

thanks in advance for any info .

Ben

[ManiacJoe]

Someone please correct me if I am wrong....

DNG is largely just a wrapper for something else. When your original raw files were converted to DNG, the proprietary raw format was converted into the Adobe raw format.

After your raw file was converted into an image by ACR or other program and saved as an image file (JPG, TIF, PSD, etc.), there is no going back to the non-image raw file.

You can put this image file inside a DNG file, but it will still be the same image file with just a DNG wrapper around it. Thus, you gain nothing by putting the DNG wrapper around it.

[BhSussman]

thanks for your reply. As i mentioned, this is just a convenience thing- I wasn't looking for any benefit of converting, just whether there would be any damage

[JP Hess]

I have been thinking about you are efforts of using DNG to keep all of your final edits. But I'm not sure what you think the DNG will do in that regard. In Lightroom, all your adjustments are stored in the catalog, not in the file. So I'm not sure what converting the files to DNG is really going to accomplish. Jeff Schewe has written in the past that he sees merit to converting non-raw images to DNG to standardize file storage. At least that is what I understood. But I think your PSD files are just as "secure" in preserving your adjustments. I don't believe there is any harm in converting to DNG. And I don't think the DNG conversion is going to deteriorate the quality of the image. But I don't think you're really accomplishing anything in the process.

Converting the PSD to DNG will not give you back all of that raw flexibility. You will not have access to all of the different camera profiles that were available in the beginning. In other words, it is impossible to make the image raw again, just like you cannot un-cook an egg. Essentially what you are doing is converting the PSD to a TIF with a DNG extension.

[BhSussman]

Thank you for your reply. Your 2d & 3d sentences from the bottom of your 1st paragraph answered my question.

[Just Shoot Me]

Stop using PSD in PS and start using TIFF. PSD is a Proprietary Adobe file format which only Adboe software can read, display and work with.

TIFF can be read by many different program. TIF retains all edits made in PS even layers.

Using DNG to Wrap up the PSD files, IMHO, is just asking for trouble down the road.

[Bob Somrak · Accepted solution]

Have you tried loading these PSD files you have converted to DNG back into Photoshop?  Photoshop considers them RAW files and does not show the layers but only a flattened image.