Hi,
I don't think that we get serious image degradation with JPEG. You could try to take a TIFF image convert it to JPEG and subtract the JPEG image from the TIFF. What remain is a difference image, it will be mostly back.
The two major issues I see with JPEG are:
1) Information is thrown away. Highlight and shadow detail that may be useful may be lost.
2) Sharpening is normally applied to JPEG images. If you rescale and sharpen a JPEG image it may show haloes.
What I have seen in my experiment was that an mazing amount of info was retained in the JPEG image, but in many other cases perfectly recoverable tonality may be lost.
Best regards
Erik
Eric I have been doing the same with my RX 100, but find that my JPEG files degrade after some editing in Lightroom. I have used JPEGS a few times to shoot with the camera HDR and love the results, but lose quality after Lightroom processing. I have been thinking of saving the JPEG to a
TIFF or DNG and working on that??