What JPG compssion amount does Lightroom' use when it creates a JPEG copy of a RAW file

[Tonybytsea]

In Lightroom Classic on a Windows 11 PC, when editing a RAW file, if I 'right click' the image and choose "Edit In..." and select a third-party app, and in the "What to Edit" pop-up select "Edit a Copy with Lightroom Adjustments" and in "Copy File Options" select "JPEG" to end up with a .jpg file, it appears that Lightroom immediately creates the .jpg copy before invoking the third-party app. What JPG compression setting does Lightroom use to generate the .jpg copy, and can it be changed?

[JohanElzenga]

I don't know the answer to that question, but I do have one advice: don't select JPEG as file type if the purpose is to further edit the file. Use TIFF or PSD (and AdobeRGB or wider and 16 bits, if the external editor supports that), edit the image and select JPEG (and sRGB if it's for web use) when you export the edited result. The quality will be much better if you do it that way.

[CMass]

Hi @Tonybytsea, 

+1 to what @JohanElzenga said. I've also included a link to our User Guide with more information on this feature here: https://adobe.ly/3T3teiy

^CM

[Tonybytsea]

Thank you CMass, for the link to information on "Set preferences for working with camera raw files in external editors". The information lists the preferences as:

File Format
Color Space
Bit Depth
Compression (TIFF only)
Template

There is no option to select the compression level for a JPG file, so what level Lightroom uses when it creates a JPG is unknown?

[Tonybytsea]

Thanks, Johan, I understand the point you are making about the limitations of JPG files. I am creating sRGB JPG images for web use, so doing a final edit in an external app as a JPG saves me having to export it afterwards. Lightroom creates the JPG and opens it in the external app. After making any edits, the external app saves it back to Lightroom, but offers no options when saving. I presume it uses the same JPG compression that Lightroom uses to create the .jpg file. However, the level of compression used by Lightroom to create the JPG in the first place and whether it can be adjusted remains a mystery.

[richardplondon]

There is another option for you: after completing LrC editing from your Raw file, export the results to JPG in the normal way, defining the output settings (destination folder, naming, metadata inclusion, JPG compression, resizing, colourspace etc) as part of that. Then in those same Export settings you can check on the PostProcessing section and in there, browse to and select the program executable for whatever version of Photoshop you are using.

Now each image is encoded to JPG, but opened into Photoshop for any further manual processing there. PS can further update the exported JPG when you Save. The advantage (if you consider it so) is that no separate external-edited version becomes visible in LrC: the PS editing has occurred onto this output only. 

Depending on what particular postprocessing you want to apply, it may be possible to streamline this e.g. invoking a dedicated utility such as Mogrify instead of full PS. That works for (say) a standardised imposition of a border. Alternatively a PS action doing [whatever] standardised steps can be encoded into a "droplet" (with a Save step included). Then this Droplet can be invoked in the PostProcessing panel of export settings. The relevant PS Action is then carried out programmatically onto each image passing through the workflow. No manual interaction with each image by you, in that case. 

Or IMHO to the extent it is possible to eliminate postprocessing by another application, so much the better. Some lateral thinking may help, for example one can lay out a series of variable aspect images, with a suitable border, onto a common sized, coloured 'background' in the Print module - and then directly "Print" output JPGs from there. Just a thought!

[Tonybytsea]

Thank you, Richard, that is very helpful indeed. "Export" offers more JPG (and other) options than "Edit in", and I can set up a Post-Processing option and save it as a "User Preset" or use "Export with Previous" when appropriate. I am also going to try selecting various third-party apps I have as the Post-Processing Application.