.jpg export quality

[richardb71045005]

If you open a .psd file in Lightroom, edit it, and export it as a .jpg, do you lose any fidelity compared to if you had just it exported it as a .jpg from Photoshop?

[dj_paige]

You always lose some quality when exporting as a JPG. There is no way to avoid this if you want as JPG. It's not different between Photoshop and Lightroom Classic.

If you export as TIF, then you should not lose quality.

[Randy Hufford]

I only use jpeg for web use. For my design and photography work i export as either a PSD or Tiff. Jpeg is a compression format and you will always lose something when doing a JPEG.

[JP Hess]

But the loss can be negligible, and sometimes JPEG is the necessary format depending on the intended use.

[Rob_Cullen]

Ps and LrC use the same 13 Quality settings, but with different number scales as follows:

(JPG Compression)

Photoshop        Description       Lightroom

0                      Low                  0-7

1                      Low                  8-15

2                      Low                  16-23

3                      Low                  24-30

4                      Low                  31-38

5                      Med                  39-46

6                      Med                  47-53

7                      Med                  54-61

8                      High                 62-69

9                      High                 70-76

10                    Max                  77-84

11                    Max                  85-92

12                    Max                  93-100

From LrC you may be 'exporting' from a raw file render to JPG.

From Ps you are 'saving' from a pixel RGB image to JPG.

So there may be differences, but the major factor is the 'Compression'.

JPG COMPRESSION EXPLAINED by Jeffrey Friedl

[dj_paige]

The Lightroom Classic quality scale is not in percent. 100 on the Lightroom Classic quality scale sitll involves some compression and some loss of quality.

[D Fosse]

Yes, important point: Jpeg "maximum quality" is not actually maximum quality. Very far from it. The jpeg algorithm will always cause data loss and added artifacts.

It's true that for one-off use it may not be significant. One single jpeg save will usually be perfectly acceptable. The important thing is to not repeat the process, because the degradation is cumulative. Don't save a jpeg over itself if it can be avoided.