When a source file is a JPG or TIF

[Nomad]

Other questions about converting JPG or TIF to DMG

I have some questions similar to frank1''s thread jpegs and DNG questions, though the situation is different. Sometimes I have to work with 'originals' that I receive in either TIF or JPG format. I understand the file size implications, but when I need to use these 'original' files as starting points for image editing, is it better to convert them to DNG (or PSD) "masters", or should I use another approach? I want to manage the images in an LR catalog. I plan to make changes to the metadata, and I also want to avoid any further destructive changes, which is why I'm wondering if I should convert the JPGs (or TIFs) to a non-destructive format like DNG before I start the editing process similar to 'editing' RAW files and recording changes to a sidecar file. Does it make sense to do this, or is there a better approach? If so, what's the best way to convert the originals, and should I do the conversion before importing into LR, or can LR do this?

 

[RipIt]

I'm wondering if I should convert the JPGs (or TIFs) to a non-destructive format like DNG

Its not the DNG format itself that is non destructive but rather the process itself of using LR to create changes to images. The fact that a DNG or RAW file cannot be "saved" makes it non destructive by default.

As to whether you should convert Tiffs and Jpgs, I see no reason. Its the process of LR that is non destructive so you can make all sorts of changes to your "original" jpgs and tiffs without actually changing their pixel data. The changes will only take effect when you export a new version of that file.

So to answer your question, I would not convert to DNG (and I do not in my workflow) If the original is Tiff or jpg, it stays Tiff or jpg.

A side reason for not doing that is so I know that the DNG file is raw data, whereas a smaller jpg file with compression gives me no more data just because it is converted but could upon filtering be confused with Raw data files.

 

[Brad Snyder]

As to whether you should convert Tiffs and Jpgs, I see no reason. Its the process of LR that is non destructive so you can make all sorts of changes to your "original" jpgs and tiffs without actually changing their pixel data.

This will work fine, if you are going to stay within the confines of ACR aware applications, i.e LR and PS. The problem will manifest itself, if you intend to use those original files with external apps. No other software will know what to do with the file adjustments embedded in XMP. So, as RipIt says, the changes only become visible to the 'external world' by exporting. The only advantages that I see to converting to DNG are minor:
1) a small compression of TIF files
2) an embedded preview of the edits, readable by DNG aware apps.

This method does have the advantage of preserving the orginal RGB pixel data forever, and applying non-destructive changes is infinitely 're-doable', so that consecutive 'saves' don't lead to jpeg re-compression artifacts.

 

[Nomad]

Thanks RipIt and Brad. I didn't realize that LR would allow me to make changes to JPGs without the saving/jpg artifact problem.

Does it change anything if I edit the "Master" jpg via: Photo menu > Edit In > Open As Smart Object in Photoshop?

 

[RipIt]

Does it change anything if I edit the "Master" jpg via: Photo menu > Edit In > Open As Smart Object in Photoshop?

No because the act of opening as a smart object will force a "save as", thereby leaving the original untouched.
You can make any enhancements within LR, open as Smart Object which will reflect those changes but at time of saving you will be forced to save as. Worth noting too that if you do this then Lightroom does not track that new file.

 

[Nomad]

Thanks. I just noticed that if i choose 'Edit in > edit in Photoshop CS3' instead of 'Edit in > open as smart object', and then choose the radio button 'edit a copy with LR adjustments', it also "saves the 'copy' as" a psd, but this way LR seems to track the new file. Is there any difference between these 2 methods other than LR tracking the new file using method #2 since both seem to require the new file to be saved as a psd?