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Question

LRC to PS. Why not to activate ZIP Layer compression from LrC to PS when ZIP compression is asked ?

Forum|Forum|3 months ago
November 12, 2025
3 replies
340 views

Dear all

I'm trying to find the best file size for a RAW send to PS for modification. The testing protocol is simple. From LrC I edit in PS with several options (PSD, TIFF with no compression, TIFF With ZIP compression, ). In PS I do the same modification (Split frequency, add a background) And at the end, before saving, PS is telling me that the document size is 753.7Mo far all options selected in LrC before (this is normal). Is is just to check that the result is consistent in all tests

1) From LrC PSD ,16 Bits, Prophoto, resolution 240. PSD File size at the end in LrC 642.64MB

2) From LrC TIFF, 16 Bits, Prophoto, resolution 240, no compression. TIFF file size at the end in LrC 1.15GB

3) From LrC TIFF, 16 Bits, Prophoto, resolution 240, ZIP compression. TIFF file size at the end in LrC 1.10GB

4) From LrC TIFF, 16 Bits, Prophoto, resolution 240, ZIP compression but at the end in PS instead of closing the file and accept the save I do a save as in TIFF. And when the TIFF windows appear, I select ZIP Layer compression. TIFF file size at the end in LrC 596,73MB

So why you are not activating the ZIP layer compression from LrC when ZIP compression is asked in LrC ?

Kind regards

Windows

ouiouiphotoAuthor

Known Participant

This morning I receive a mail from Adobe asking me "Did you get the answer you needed?" and to rate the good answer. But unfortunately there is no good answer so far. Is this non usage of ZIP compression of Layer when editing to Photoshop from Lightroom even if you ask Zip Compression is a regression, a miss or as designed and then why not to use it.

Adobe communicate that TIFF should to be the preferred format between LrC and PS, one of the reason is compression, but this is incorrect because PSD consume less hard drive space that TIFF. TIFF is better only if you activate the Zip compression of layers

On my 8TB Hard drive 4.7 TB as used by 5148 Tiff files when this can be reduced to probably less of 1.5 TB just by activating the ZIP layer compression

.Sheepdog trying to help Lightroom and Photoshop beginners

E

ExUSA

Legend

I'm not sure what you are asking but Lightroom sends a flattened image to Photoshop from a RAW file. There are no layers besides the background.

ouiouiphotoAuthor

Known Participant

Yes but you create layers in PS for your final dev/retouch work. And Those layers can be zip compress when you save. But even if you select ZIP compression in LrC they are not in the final TIFF

.Sheepdog trying to help Lightroom and Photoshop beginners

E

ExUSA

Legend

You don't specify that in Lightroom. Its a save option in Photoshop.

dj_paige

Legend

File size is largely irrelevant; it is the wrong measure. Optimizing file size is not the same as optimizing image quality. Compressed files will naturally have a decrease in quality compared to uncompressed, although you may not be able to actually visually discern the differences between an image that is compressed and the same image uncompressed.

ouiouiphotoAuthor

Known Participant

In this case, final file size is the right measure because all the files are the same with the same quality. The compression is lossless. So You can have a final file size from 596Mo to 1.15Go from the same quality at the end. A ratio 2. For some more complex files with more layers, the ratio can be 3 to 4. The point here is that in LRC you can activate a lossless compression going to PS, but this is not fully implemented, and the gain is very low compare to what can be really done. Can be "as design" and I don't know why or a "bug"

.Sheepdog trying to help Lightroom and Photoshop beginners

ouiouiphotoAuthor

Known Participant

That part might be ancient and never updated. If you find that PSD gives better compression, then I see no reason not to use it.

Last updated on Jul 29, 2024 so not so ancient. The point is that for existing TIFF there is no easy solution. You cannot just save in PSD instead. LrC will not keep the link. A way to be more efficient is to create a script that will save the file, with the ZIP Layer compression activated. So you can convert the existing ones to a more compress version and LrC will keep the link. BTW i still don't know if it is a bug or as design. And I will probably never know here because this bug report has been moved, as usual, in Discussion with not explanation from Adobe. It is not the first time that a bug is moved in discussion without any check from adobe and finally moved back in bug after confirmation from other users. I will try to have my answer by other channels.

.Sheepdog trying to help Lightroom and Photoshop beginners

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