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

[ouiouiphoto]

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 

[dj_paige]

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.

[JohanElzenga]

Compressed files can be losslessly compressed, in which case there is zero impact on image quality. ZIP-compression is lossless.

[dj_paige]

Okay, that seems to answer the question about how to compress files, use lossless compression. It also ends the question about the value of looking at file sizes.

[ouiouiphoto]

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"

[JohanElzenga]

I think the answer is simple. ZIP layer compression is relatively new, so it has not been implemented (yet) in Lightroom Classic to Photoshop. The engineers can only do one thing at a time, so there is a priority list and this is low on that list (if it's on the list at all). Use PSD, as you have shown, the difference in file size is not very much (less than 10%).

[ouiouiphoto]

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 

[JohanElzenga]

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.

[ouiouiphoto]

Taken from Adobe Web Site https://helpx.adobe.com/lightroom-classic/help/supported-file-formats.html . What is funny is that they speak about compression, and it is not the case, as you can see in my test. That's why I wonder if it is a bug/regresion 

[JohanElzenga]

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.

[ouiouiphoto]

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. 

[JohanElzenga]

I know that the page was last updated on Juli 19, 2024. But that does not mean that the part you quoted can't be very old.

Reports placed in 'Bugs' are usually moved to 'Discussions' until the report is verified as being a real bug. The vast majority turns out not to be a bug, because many people think that any problem with a computer is a 'bug'. They think that 'bug' is just a fancy word for a problem with a computer. I bet that this problem is 'as designed'.

[ouiouiphoto]

In the support I manage for my company, we downgrade the ticket after checking and not before.  And when I open a ticket, I always give a lot of detail that allow the support team to check and confirm or not. Will see if your bet is the good one if I receive an answer 😄 

[ExUSA]

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]

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 

[ExUSA]

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

[ouiouiphoto]

In LrC you specify that you want a ZIP compression. And the layer are not Zip compressed at the end. On The LrC file format web page Adobe specify that Tiff is better for compression and should be prefered to PSB when going to PS. But it is not because the Zip Layer compression is not implemented in LrC when going to PS. So either the web page is wrong either there is a Bug/regression/miss in LrC

[ExUSA]

Photoshop handles file saves. Are you using the Zip option when saving from Photoshop?

[ouiouiphoto]

If you open in PS from LrC and you close the file after modification in PS.  PS ask you to save, and you answer yes, and you are back in LrC. You don't see any saving option from PS. If in PS you make a Save (CTRL+S) you will not see the saving option neither. The ZIP compression option is in the LrC preference. To see the PS saving option, you have to make a save as. 

[ExUSA]

I'm aware. There are a number of options in Photoshop for file handling that aren't exposed with a simple save.

[ouiouiphoto]

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  

[ouiouiphoto]

Hello. For those who may be interested in the topic:

I have succeeded in gaining 3 TB just by activating the ZIP compression of layers, which is not automatically enabled by Lightroom when editing a TIF file in Photoshop (PS), even if TIF compression is already active.

By the way, I still wonder if this is a bug, an oversight, or by design—and if it is by design, why?

To achieve this, I created an action in PS to save the TIFs with the layer compression active and executed this action on my more than 5,000 TIF files. It was not straightforward because PS cannot execute an action only on TIF files within a directory containing other file types. Therefore, I had to create some scripts.

And then, was it useful? Is 3 TB nothing? Yes and no. When you establish a 3-2-1 backup strategy (3 copies, 2 in-house, 1 outside), you can use the cloud as a destination for the off-site copy. In solutions like Backblaze, which is one of the less expensive options, this saving translates to approximately $200 in yearly savings. So yes, it was useful.