How to use PhotoLab on multiple Apple Computers

@John7 That makes sense I hadn’t got round to testing that so deleting the directories via PL5 eradicates them from the disk and the database. The situation that concerned me was deleting them from disk (not via PL5) when I suspect that they will remain in the database.

One thought that I have but requires DxO to implement it is to have a preferences options

  1. To write Uuid free DOPs (or a DOP with a special “wildcard” value) and then overwrite the database when importing such DOPs or create VCs if the date of the incoming DOP is earlier than the date of the database entry or…
  2. While this would work for future implementations another option would be needed to ignore DOPs with Uuids that exist from before such a strategy.
  3. The date time check could be made optional i.e. always accept the incoming DOP and overwrite the database editing details etc.
  4. I have not even vaguely explored all the ramifications of such a scheme.
  5. I have directories in the database where I have managed to screw up PL5 so I also want an option where I can leave the data intact on disk but expunge the directory from the PL5 database!

Problems only tend to arise if you swap between computers on a regular basis.

If you ingest your camera’s files onto your laptop and work on them in PL there, as long as they have never been seen before on your desktop computer, all you have to do is to copy them, together with their DOP (and XMP) files to the desktop machine. Your desktop will then add them to its database and function perfectly normally.

However, if you were then to work further on those images and then copy them back to your laptop, PL on your laptop will quietly blow its cool in trying to reconcile the original versions that it knows about in its database and the versions of the DOP files it will then read from the files you have just copied back to the laptop.

As long as you only ever perform a one-way move (not a copy) from your laptop to your desktop, thus deleting the originals from your laptop, you shouldn’t have any problems.

I would like to see an option where PL does NOT store metadata for visited directories so that you can explicitly catalog a directory. It would also be nice to have the ability to un-catalog a directory. You then have full control over what is in the database.

I feel rather out of control with how everything is as it stands now. I would also like to have the ability to have multiple databases and you can then select which one to use. LR and PMP do this.

Looks like a reason to delete the database once a time and have PL build a new one.


I think I understand now, and thanks for all the above. Apparently there are two (or more) scenarios. What I will not do, is have two (or more) computers, each with PhotoLab, which I use back and forth, each containing new PL information ever time I do this. I might very well end up with a folder on each computer with the same name, as the folder names are generated by Photo Mechanic. I have no intention to do anything like this.

For me, I will always use my desktop computer when I am at home, and always use my laptop when I’m away from home. Since Photo Mechanic names folders based on the date, thanks to what you’ve all written I will refrain from editing photos on any given day with both computers. This means I will not have the problem we are discussing up above… and means anyone in this forum that uses two computers can avoid any issues as long as they don’t ever end up with the same folder names on both computers. PhotoMechanic can prevent this issue, if we allow PhotoMechanic to name folders in a logical manner.

(Not sure what happens when I visit India, and the “time” photos are taken is based on local time, but I suspect PhotoLab only applies to the TIME, and ignores the TIME ZONE.)

Is there a potential problem if someone crosses time zones, as in when I travel to/from India, or others travel to different countries? Does PhotoLab use the local time, or does it consider the time zone?

@mikemyers I am glad it makes sense, when I write some of this stuff late at night I sometimes wonder if it makes sense (to me let alone anyone else)!

There are a raft of issues that need to be resolved if DxO were to go down the path I “suggested” however there are timestamps in the DOP and I don’t believe that they currently control (gate) anything (needs checking because I asked @sgospodarenko a question about this in a post PL5 Repair creates "surprise" straight line selection elements while attempting to create a circular mask! - #11 by BHAYT and the response was

Having got Svetlana’s response I then “ignored” it because changing Uuid’s was easier and produced the results that I was looking for, instant VCs! I will try a test where I change the timestamp in the DOP (leaving the Uuid alone) and see what happens?

In truth I do not believe it is hard to implement such a scheme nor to take timestamps into account or simply (optionally) ignore them(!) but DxO have other development priorities, 5.1.1 has just been released.

I will test @John7 idea of deleting a directory to clear a path for (re-)importing except that there is no command to delete an entire directory! Deleting the contents as John actually stated is possible so I will test that. However, renaming a directory is possible to e.g. _saved_2021-12-17 and that will keep some options open to prevent complete loss of the data but might then pose problems later!

Sadly PL5 is not a full blown photo file manager and has no copy, move etc commands for files or directories but when you think about the work necessary behind the scenes to keep the database in step that is not really a surprise!

Its the image folders I work with, not data base. If images are added to the DAM after being added to PL doesn’t pick up the keywords added in the DAM for export. Fooling it into thinking its a new folder of images works and it adds the keywords.
I use Syncovery for backing up (just the) changes between desk and laptop and the only program I run to pick up changes or added keywords is Photo Supreme on the receiving machine. If I don’t do that the images can’t be found by a search or any added keywords can’t be used when adding images on that machine. PL just accepts the edited images no problem, no virtual images or anything. BUT clearly I have to ensure both lots of programs are the same versions.

@KeithRJ, some of your wishes have been catalogued in here:

Hypothetical question. Suppose I’ve been using PL5 for the past few months to take photos of, say, penguins. Then I decide that for future access, I want to create a brand new folder, Penguin-Photos (or whatever), and using Finder on a macOS computer, I drag all the folders from where they were into this new folder I’ve created.

My question - will PhotoLab just accept this new file arrangement and work with it the next time I open PhotoLab.

Follow-up question - suppose I have Penguin photos on bot a. desktop and a laptop. I assume I can copy those over from the laptop as I’m already doing, and PhotoLab will accept this.

Assuming keywords for each image, and ratings for each image, and so on, will be stored in a file along with the image file and the .dop file, so if I’m moving full folders around (not just individual images) everything should still work well.

I’m assuming that there is no way now, and no way planned for the future, where all these images can be placed on a “server”, so more than one person can work on images simultaneously. (This would be wonderful for the eye hospital I volunteer at in India, but I’m assuming it’s not possible.)

@mikemyers I am just a user like you but one that got very curious about how/why I was encountering Virtual Copies and tried to create a test that would narrow down the reason for their creation, hence the various posts that identify the “problem”.

I did carry our the tests I suggested with respect to dates etc. I had already done them for Ratings etc. in the past and basically “hacking” the values does not work, PL5 uses the database values to undo the hacks on the next DOP update, it may not actually realize that the values have been hacked but is simply doing a DOP update, i.e. copying the database contents to the DOP because my “hack” changed a file date/timestamp!

This changes if the Uuid is changed, PL5 immediately recognises that something has changed in the DOP and a Virtual copy is instantly created. If any other fields have been changed and all the changes are made before the Uuid change and the DOP then saved then the new Virtual copy will include the changes.

If you change a directory name then PL5 is perfectly happy with that and when you navigate to the newly named/re-named directory PL5 will not greet it as a long lost friend but as a brand new friend (according to my tests).

Similarly if you add new photos to a directory they should be recognised for what they are, new items! Ratings are already stored in the ‘xmp’ sidecar file as are keywords etc, only the tag (rejected etc.) appears to be stored only in the DOP. Keywords in the DOP currently appear to be ignored if you change them by hacking the DOP PL5 will restore the DOP to the state it has in the database and undo the hack.

If you remove the DOP and update the ‘xmp’ file with new keywords etc. that should be acceptable, PL5 should use the edit values it has in the database to create a replacement DOP. (Needs to be verified)

But if you want to introduce new editing from another machine via the DOP then you are heading for a problem because you are going to get a Uuid clash and Virtual Copies, unless you remove that photo from the target system. You can delete via PL5 but I tested deleting via file manager and adding the photo back in and it appeared to work just fine (I need to repeat the process with the DOP “hacked” to give it a new Uuid just in case the test is faking good).

PL5 is only interested in photos etc. in the context of the directory they are in, throughout my testing I am using copies of the same base set copied to a new directory and tested/re-tested and there have been no issues.

The final question is not one for me I am not a DxO developer just a user who should be editing his photos not “hacking” PL5!!! It is a question for DxO and like all such requests for new developments must compete with those that DxO believe will give it a competitive edge or at least maintain their position.

I hope that this helps and the tests with photos deleted and replaced fits with the way that @John7 is using his systems (I believe).

I need to make a disclaimer that what I write here is based almost entirely on basic testing of the product but I can get things wrong although most of the above has been tested and I stand by what I have written with the caveat that should means I need to do some more testing!

At the moment, PL5 has a bug wherein it fails to properly record time zone in output JPG images for the ‘original date/time’ tag, as shown attached screenshot. Instead of the time zone in the original raw file, it records the time zone as “00:00”. However, the ‘digitized date/time’ tag records the time zone properly, e.g., “06:00” I’ve reported this as a bug to DxO but haven’t heard anything back. PL4 didn’t have this bug.

I haven’t been to a different time zone since Covid, but there may be time zone problems with PL5. For what it’s worth, some photographers always set their camera clocks to UTC to minimize such problems (not just w/ PL5…).

Here is a different setup that solves some problems you are having but might be creating new ones. I have a desktop and a laptop, one on windows 10 and one on windows 11. I store all my images in OneDrive via the Lightroom catalog (I use LR about 10% of the time). I process most of my images in PL 5 (much preferred to LR) on either my desktop (which has a very poor 32-inch monitor currently) or my 13-inch laptop with a 4K screen with good color. All image files are on OneDrive. To speed up getting through large numbers of images from a long photo shoot, my latest process is to do the initial culling and processing on the desktop and the final edit on the laptop to make final color adjustments and any further cropping or exposure adjustments as required. I am doing this way because the laptop sometimes chokes on heavy processing of hundreds of images. The two different versions of PL5 on different computers can usually see the adjustments made on the other computer. I can fairly easily switch back and forth. When I travel, I can store fresh images on OneDrive and can access all existing images, provided I have a decent wifi connection. If not, I can store them locally and transfer later. I do get notices from Windows about duplicate files (not images) created by PL5 but Windows saves a version with a slightly different name, and I move on. I will be making some hardware changes in January but plan to stick with cloud storage. I think this will work long term, but I am a little concerned I am causing future problems. I will read this thread a little more carefully when I have time and learn about the PL5 database quirks. Before someone asks, I have a terabyte of storage on OneDrive from my wife’s family subscription to Microsoft Office and another terabyte on Google Drive that comes with Google Fiber.

As I read what you wrote, IF your desktop is a better “computer” than the laptop, cpu, memory, etc., then it sounds like a good-size calibrated monitor would be best for you. You could probably. use it on both your computers. That means spending several hundred dollars, at least. Since your images are going to eventually go on your OneDrive, and since your laptop “chokes” on too many files, that’s one more reason for getting a newer display, (preferably in addition to what you have now, not “instead of”). A year or two ago, everyone here insisted that before I do anything else, I needed a calibrated display. Without it, I was just wasting time.

My gut feeling was to get my images edited, before filing them away. If you do this on your laptop, everything will be fresh in your mind. That’s one of my problems right now - I spent a week away, captured lots of images, came home, and copied them to my desktop - but now I’m fighting to find time to work on them, as I’m always doing NEW stuff. I am a happier person if I can work on images the same day I took them. If so, it’s “fun”. A week later, it starts to feel like “work”.

But the flip side to that is while I’m away, I’m constantly finding new things to do, and unless I stay up half the night, I don’t get a chance to work on the images I just took…

New hardware is a January priority. My wife loves her M1 MacBook and is strongly suggesting an iMac to upgrade both monitor and computer hardware. It’s kind of funny. If I wanted to buy a $2,000 camera I would get a very lukewarm response but she loves upgrading computer hardware.

On a trip to Europe last month, I spent so much time trying different backpacks and downsizing my camera equipment to fit, I managed to leave the power cord for my laptop behind. I got to process the first day’s images on battery power and accumulated images on SD cards thereafter. I wouldn’t have done complete processing but mainly just review for exposure mistakes, color and composition.

I’m going to be bold and, possibly, controversial…

As far as I can see, there are two options - 1. use the database for image edits - 2. use DOP sidecars for image edits.

Why, when it contradicts the well known software design principles of KISS and SPOD, do both get used at the same time?

  • Keep It Simple Stupid
  • Single Point Of Definition

Version control has always been a pain in the neck, ever since the days of the Microsoft’s Briefcase model.

In fact, possible Lightbulb :bulb: moment - how about PL allowing the marking of folders as “briefcase” folders, where DOP files will be merged without reference to the database?

Or, of course, I could be talking complete nonsense :crazy_face:

Joanna (@Joanna) it is not a stupid idea because that is effectively what I said about “promoting” virtual copies, i.e. cleaning up any mess quickly and easily and then went on to describe the idea of the “promotion” process being implemented as part of the re-import of any directory.

However, I saw this as a database wide feature and you are proposing a solution with greater granularity so that any directory can be assigned this “briefcase” feature which is even better. Having both added to PL5 would suit me.

However, in the meantime deleting and adding back the deleted files will work BUT this must be done in such a way that PL5 recognises the deletion and expunges the photos or directories before they are re-introduced. Doing both operations one after the other with PL5 active seems to work. If the deletions are done while PL5 is shut down that is fine BUT PL5 must have an opportunity to adjust to the deletions first before it finds the new overlapping content.

Kevin (@isthisnametaken) I am confused about your onedrive use and also jealous with an upload speed of 0.5 and a download that has shrunk from 12 to 4 the cloud is a complete no/no!! You state that both machines can see the adjustments made by the other computer and that you switch back and forth.

Your model is similar to one I tried where I wanted to split the export load between two computers so one held the photo and the local DOP and the other accessed both across the LAN. It works only as long as PL5 on either machine does not update the DOP as soon as the DOP is updated then Virtual Copies will ensue or at least that is what my tests indicate and I ran into that problem when I changed the Tag(red/green/grey) on one of the machines and got Virtual copies on the other!!

You can turn DOPs off in the preferences but then the second machine would not have a clue about the editing updates made to the photo!?

Incidentally if DOPs were stored separately to photos then …, it wouldn’t work because all you would be doing is working on your local version and not able to see the edits done on the other machine!!

So Kevin while I am glad that you appear to be defying the problem the rest of us are experiencing I would like to know how. But I will run a test by putting a photo directory on my NAS and trying edits from both of my machines at the expense of one of my licence seats!!

Has anyone noticed the change in the trial conditions? In the past (don’t know if it changed on PL4) you could continue to use the trial but any exports would be watermarked now that my trial copy of PL5 on my test machine has lapsed that is it, activate or nothing. This no worse that other software suppliers but a little disappointing!

Update 1:-

NAS testing (simultaneous opening):-

Copied some photos that I have been using for testing to my X drive (NAS drive 1). Opened in the newly licensed (begrudged) test machine (T) and navigated to one of the directories. With that version of PL5 open I did the same on my main machine (M) and instantly got virtual copies on the T.

NAS Testing(only one machine open at one time):-

Will now repeat the test with T shut down after navigating to the directory before opening and navigating on M. Then shut down M and open on T. No edits at this stage just opening the directory. Worked fine with no VCs.

Now with editing:-

Will repeat with editing. Edited a photo on M and shut down. Re-opened on T and all o.k. and the edit made on M is visible on T! Made another edit on T and shut down. Opened on M and the T edit is visible made another edit on M and shut down. T found the edit and no problems!

Export on T:-

Changed Noise reduction to none and exported on T and shut down. Opened on M, noise reduction as left on T exported photo all O.K. The current exports on both machines are different, different suffixes and different locations.

An apology to Kevin:-

Kevin (@isthisnametaken) I owe you an apology for ever doubting your word. Providing the opening is strictly one machine at a time it works for photo edits. I will repeat the tests later and include keywords and export with the same suffixes and locations.

As mentioned e few times before, I don’t get virtual copies. So why???


@George The answer to you question is that I do no know!

The test was conducted exactly as described and T reacted to M opening the directory on the NAS as I described!

Previous tests where I have been accessing photos located on M from T simultaneously in order to export 50% on one and the other 50% on the other (using my existing two slow GPUs instead of buying one faster one) seemed to work until I made a rating change or did something (!?) and then VCs.

Currently I don’t know exactly what is going on except that the method I tested where only one machine accessing at a time worked needs to be repeated with M hosting the files instead of the NAS (and it should work with M doing the hosting) both machines are set up so it is an easy job but I need to block a hole being dug by foxes under out garden office first!

I will do that test and study the DOPs and the database and then investigate simultaneous access again, including a study of the DOPs and the database and see if I can wrap my head around what is going on and what might be triggering the VCs or not as the case may be.

The ‘Unwanted Virtual Copies’ topic ran for about a year and I was always staggered that DxO had not waded in at some point and set the record straight!

I thought that the unwanted vc’s was also on winwdows, where I’m on. Maybe somebody can confirm that?


@George I am running on Windows (both machines are Win10) and have had possibly conflicting reactions from my various tests. I have looked at your posts in this topic and you are using a similar configuration (I believe) to the one I use in my tests. 1 x NAS (DS220J) + 2 x Win10 machines both with PL5.1.1

You may well have described your workflow in a previous post but can you humour me and describe how you set up your system and the workflow you are using, whether you have both copies of PL5 active at the same time and what updates you make on both sides of the “divide”.

In one of your posts you state that you delete a directory but it comes back on the next synchronisation. Exactly how and where is that deletion done?