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ouiouiphoto
Known Participant
November 12, 2025
Question

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

  • 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 

3 replies

ouiouiphoto
Known Participant
November 20, 2025

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
Legend
November 12, 2025

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.

ouiouiphoto
Known Participant
November 13, 2025

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
Legend
November 13, 2025

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

dj_paige
Legend
November 12, 2025

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.

ouiouiphoto
Known Participant
November 12, 2025

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
JohanElzenga
Community Expert
Community Expert
November 12, 2025

It was already existing in 2012, so this is a relative "relatively new"  😉 That why I'm wondering if it not a regression or if this was never consider. As you say, there is a workaround. But Adobe communicate on the TIFF format, telling it is the best between Lightroom and Photoshop for compatibility issues 


Do they specify those compatibility issues? As far as I know, the only reason to consider TIFF over PSD is if your image is getting between 2GB and 4GB. The maximum size for PSD is 2GB, while TIFF supports up to 4GB, if I remember correctly.

 

-- Johan W. Elzenga