Loss of image quality when importing and exporting in Lightroom for the purpose of metadata only

Hi Barte,

Interesting question, I have never thought about that.

I'm confident that it would not cause any degradation to the image. The reason is that you haven't DONE anything to the image that would cause it to resave. If you made a change to the image such as size, image quality, etc., that would cause a resaving of the data which might cause degradation. But when just exporting an image that exists within the catalog, there is no change in the image.

Keep in mind though that the image is likely to change its storage size IF you export it with a different amount of compression than you did when first saved. Let's say you originally compressed the image at (say) 70%, imported it into LRC, and then exported the image at 100%. The image will be larger than originally. If you took the same image and Exported it now at 60%, it would be smaller than the original. At that point, there may be degradation. Lastly, if you exported the same original image at 70%, it will export at the same size.

One last thought: if you only wish to have access to the same image with no changes to it whatsoever, another option would be to right-click on the image and look for "Show in Finder/Explorer." From there you can copy or duplicate-drag the file to another location on your hard drive, and it will be the exact image you have in LRC but without any changes, you may have (or have not) done.

After seeing all of these comments I did a plain and simple test, Here's the way to do it:

When you import, -> Add <- the images into Lightroom from wherever they are, do NOT MOVE them into another folder.

Assign keywords as you wish, then Select them all and then do a Command/Control-s. This will save the metadata to the image.

Finally, go back to your orignal foder in Finder/Explorer and do what you want with the image. 

And finally finally, in Lightroom delete the images from your catalog since you will not be doing anything with them in Lightroom at this point.

Do NOT Export them out of LR. If you do, you will be doing one of the jpging a jpg issues that are talked about above. Saving the metadata to a file does NOT change the pixels, it just adds the metadata to the file. Two different things.

Good luck!

One other alternative is to use Adobe Bridge. From there you can access all of the Metadata options and never do anything to the image(s) other than select them, open the Metadata window (Control/Command-i), enter what you want for the image(s), and then close the window. The big negative is that you cannot change the image selection(s) with the Metadata window open so it may be a bit slower than you'd like but it will not touch the image quality.

Good luck!