23 Replies Latest reply on Oct 19, 2016 9:49 AM by johnrellis

    What part of "NO" does Adobe not seem to understand?

    MKSA Level 1

      I am actually quite sick and tired of the shoddy, weak and untested "programming" going on at Adobe these days.

       

      I have a Lightroom catalog of 118,000+ images. About 3 months ago I deleted all previews and re-rendered everything as 1:1 previews.

       

      I then of course have Lightroom set to a nice little setting (which does not work) which is "Discard 1:1 Previews" set to NEVER

       

      That process took over 57 hours to render 1:1 previews for this amount of images, now 3 months later I go to some images to start processing them and lo and behold Lightroom now wants to sit and re-render all the 1:1 previews. Wanted to process a time-lapse today of 790 frames from a D3x and had to wait for Lightroom to re-render all those previews.

       

      You cannot believe how much time Adobe wastes for me, Photoshop CC 2015.5 is a disaster and Lightroom 2015.7 appears to be turning out into an utter disaster too. Really not sure how Adobe can be selling "professional" software products aimed at "professionals" when people during their workday must lose time waiting for the software to do something they already did.

       

      What is up Adobe? No updates or fixes for Photoshop yet despite lots of complaints on these forums and it appears no updates or fixes for Lightroom either.

       

      This is what I call productive software.

       

      This also has nothing to do with disk space problems or anything, all my hard disks including those containing the image files, previews folders and catalog files are all permanently running at 40% free capacity across the board.

       

      Screen Shot 2016-10-12 at 4.33.37 PM.png

        • 1. Re: What part of "NO" does Adobe not seem to understand?
          99jon Adobe Community Professional & MVP

          I cannot even begin to understand the need to generate 118,000 1:1 previews.

           

          The develop module uses raw data or fast load data for DNG’s ; not previews.

           

          After each shoot I import using standard (auto) previews at medium quality which is normally sufficient.

           

          After culling (picks and rejects) I only need to generate 1:1 previews for the keepers e.g. for checking focus and editing.

          • 2. Re: What part of "NO" does Adobe not seem to understand?
            MKSA Level 1

            Firstly, I do not use the develop module of Lightroom, it's slow, sluggish and frustrating and all the controls and sliders are sluggish and inaccurate. I edit everything in camera raw in Photoshop, it works for me and I like it that way.

             

            Why do I generate 118,000 preview at 1:1 ?? ..... well ..... this is a catalog of images spanning 13 years .... they are all pretty much keepers and my deletions are done each time I import. Yes I really do have LOTS of keepers and I have a lot of stacks of time lapses and panorama's that I eventually get around to processing.

             

            I only use Lightroom for my cataloging, so I am only using the Library module, when I need to browse through images when selecting images to process for my agency I need to see the preview instantly not wait for Lightroom to go and re-render what I already rendered.

             

            Lightroom USED TO work this way, I know this for a fact because I have been using it since Version 1.0 and in those good old days when it had barely 90% of the functionality it has today, when I went to 1:1 previews I had already rendered months before they were there and would display instantly. It's only the last few versions of Lightroom that is now truly wasting my time waiting for previews to re-render.

             

            So the question is not why I choose to generate 118,000 1:1 previews, the question is why does Lightroom IGNORE my setting of "Never Delete my 1:1 previews".

            • 3. Re: What part of "NO" does Adobe not seem to understand?
              99jon Adobe Community Professional & MVP

              OK I understand and agree that the full Library previews should be retained if you have set the prefs to “never”

               

              I’m not sure if this relates to changes in recent versions - re-generating previews on the fly for the next image (advanced) in the filmstrip. Maybe an Adobe staff member can help.

               

              I detect that there is a move towards using smart previews to overcome performance deficiencies until LR is re-written from the ground up.

              • 4. Re: What part of "NO" does Adobe not seem to understand?
                MKSA Level 1

                I think the problem crops up every time they release a new version, it comes with a new embedded camera raw and I think there is a bug that Lightroom thinks it now needs to re-generate all the previews. Very annoying and time wasting.

                 

                I set a selection of my Namibia images 22,000+ last night to re-render 1:1 previews (Macbook fan going all night long) and now this morning I can fly through the high res previews quickly picking the one's I want to edit.

                 

                The difference already is that I have edited 50% more images this morning than by any other morning at this same time of day, so this previews issue literally cuts my work week in half.

                 

                I have not even looked into Smart Previews yet, I will take a batch of 1000 images and play around with Smart Previews and see if that will be the solution for the time's ahead with Lightroom. I really hope they find a solution to this even if it be smart previews but then stick with it and not go changing it in 3 versions time.

                • 5. Re: What part of "NO" does Adobe not seem to understand?
                  MKSA Level 1

                  Spoke far too soon, was working fine this morning then came across a star trail of 98 images whose 1:1 previews were already rendered overnight. The moment I clicked on the first one Lightroom starts re-rendering what it spent all night doing.

                   

                  I am furious now. This has wasted 2.5 hours of my day already and now Lightroom is behaving like an utter little PIG with my CPU and memory.

                   

                  Now currently waiting 2-3 minutes for each 1:1 preview to re-render because Lightroom in all it's brilliance is doing something in the background but of course there is no progress bar and no way to find out exactly what it is doing. My fans are going full speed non stop and there is simply no progress bar indicating that it is doing something.

                   

                  Then tried my usual EDIT > Open as Layers in Photoshop which I do almost 5 times a week and now it just freezes and eventually says "cannot launch Photoshop cc". Then I try again and it eventually opens photoshop and starts loading the layers (only 98 images) and it took nearly an hour before I killed Photoshop and Lightroom ..... that normally takes me the better part of 5 minutes to load 100 images into layers in Photoshop .......

                   

                  I am finished ..... might as well just give up because Adobe clearly has given up trying to fix anything.

                   

                  Not a word from Adobe .... well, I guess that's to be expected.

                  • 6. Re: What part of "NO" does Adobe not seem to understand?
                    MKSA Level 1

                    An ENTIRE day wasted .. had to delete all Lightroom and Photoshop Caches, had to delete all previews and now must re-render them ALL AGAIN, WHAT AN UTTER PIECE OF USELESS RUBBISH ADOBE "CREATIVE" SUITE IS. Nothing "creative" about it. Have to explain to my agency why they only got 100 images this week and were expecting 350+ ...... Adobe just doesn't give continental  STUFF ...... and STILL no reply from ANYONE at ADOBE ...  there's a DO in the word ADOBE .... it stands for DO DIDDLY SQUAT while we ADOBE get rich ...... sick and tired of this utter BULL !!!! Took me 5 years to get my foot into the door if this agency .... and now cannot deliver the good's quick enough .... THANK YOU ADOBE ..... enjoy your fancy office lunches tomorrow and having fun eating donuts while you continue to write crap software !!!!

                    • 7. Re: What part of "NO" does Adobe not seem to understand?
                      john beardsworth Adobe Community Professional & MVP

                      MKSA wrote:

                       

                      Not a word from Adobe .... well, I guess that's to be expected.

                      Yes, since it is a user-to-user forum.

                      • 8. Re: What part of "NO" does Adobe not seem to understand?
                        john beardsworth Adobe Community Professional & MVP

                        MKSA wrote:

                         

                        Then tried my usual EDIT > Open as Layers in Photoshop which I do almost 5 times a week and now it just freezes and eventually says "cannot launch Photoshop cc".

                        There is a bug in that area. Open Photoshop yourself first, and then launch Open as Layers.

                        • 9. Re: What part of "NO" does Adobe not seem to understand?
                          Jao vdL Adobe Community Professional & MVP

                          If you don't use Develop I would strongly advise against using Lightroom. You're far better off using something like bridge or photomechanic if you use camera raw/Photoshop to edit. it sounds to me like you are using it as a file browser which is just not its strong suite. Second, i can't imagine EVER needing to render 1:1 previews of so many images. That's a complete waste of time and resources. You should make sure your standard previews are optimal size. 1024 pixels is WAY too small on any modern computer. You should choose optimum for your display there. It appears you are using a retina screen which needs high resolution previews, probably the 2560 pixel ones.. In fact this is probably why Lightroom keeps rendering your previews because it doesn't have the correct previews for your display size But only a 1:1 giant one and a way too small tiny 1024 pixel one.

                          2 people found this helpful
                          • 10. Re: What part of "NO" does Adobe not seem to understand?
                            99jon Adobe Community Professional & MVP

                            jao makes some good suggestions. Also bear in mind that previews are only used in the Library and output modules (web, print, book etc) and not in Develop. The develop module pulls in data from the camera raw cache or fast load data when using DNG’s.

                            1 person found this helpful
                            • 11. Re: What part of "NO" does Adobe not seem to understand?
                              MKSA Level 1

                              Hi Jao, I've been using Lightroom for so long and never had problems until recent versions. I actually used to use the Develop module as well as the catalog functions of Lightroom but for the past few versions I have stopped using the develop module because it is so damn slow and unresponsive and also inaccurate, which is strange because technically it is just camera raw in disguise. So when I do find an image I want to edit I right click > edit in Photoshop CC 2015.5, then it opens, then I minimize the file and go Open Recent > and open the file I just minimized and then it opens in Camera Raw. Yeah, tell me about it, great workflow but it works and gets me my image open in camera raw proper where I have much more control and accuracy. Ok so that's one part of my workarounds with Lightroom and the less than optimal develop module.

                               

                              So yes, I am pretty much just using it now for cataloging and finding images that need to be edited. I did give Bridge a try but found it to be quite slow at indexing folders, photos, their sidecar files and all the keywords. I just could not get Bridge to function quite like Lightroom (not that it is) and could not quite get used to the interface and layout. Perhaps giving it another try is on the cards. I will however also check out PhotoMechanic too.

                               

                              You DID however hit on something regarding the initial preview size and screen resolution. I had mine set at

                              Standard Preview: 1024 pixels

                              Quality: High

                              Discard 1:1 previews: Never

                               

                              I have now changed it this morning to:

                              Standard Preview: (Auto) 3360 pixels

                              Quality: High

                              Discard 1:1 previews: Never

                               

                              Now it is taking a little longer to render those initial previews BUT when I open them they are clear and visible immediately. So I hope that fixes part of my problem and I will report back later today once I have been working with Lightroom set this way now.

                               

                              NOW, another big problem I detected, something kept saying to me there must be some kind of file permissions issue or something because of the way my Macbook fans were spinning out of control for the past 60 hours.

                               

                              This morning I woke up and opened a set of +- 8,000 images I had set to render 1:1 previews overnight. Browsing through them was fast and snappy as I expect it to be but then suddenly I clicked on one image in that batch which had previously been edited and the moment I did it took 2-3 minutes for it to render the preview and of course the Macbook fans went mad. All other undeveloped images were fine when browsing the 1:1 previews just the one that had edits done to it caused the madness.

                               

                              I opened the Mac Console App to see if anything regarding permissions was being logged by the system but nothing showed up there. So I then right-clicked on that one image that caused the problem and  > Show in Finder

                               

                              The .NEF image file itself had Read,Write,Execute permissions for all users (myself,staff,everyone) BUT the sidecar .xmp file had only my username set to Read,Write,Execute but "Staff" and "Everyone" only had read permissions.

                               

                              This is truly what I find strange because I have done a "chown" and a "chmod" across the entire drive that contains my photo files already months ago when I experienced a similar problem with ownership on some files that was causing Lightroom to go mad.

                               

                              What I find even more strange is that Lightroom is the one that created all the .xmp files (as I have it set to do) but it for some reason when creating the sidecar files did not obey the hierarchy of permissions set on the drive.

                               

                              I fixed that problem this morning with a simple

                               

                              sudo chown -R myusername:staff /Volumes/PHOTOS/

                              sudo chmod -R ugo=rwx /Volumes/PHOTOS/

                               

                              I then went and did the same to the .lrpreviews folder for Lightroom because I checked that too this morning and the catalog file had Read,Write,Execute permissions for all users (myself,staff,everyone) but the brand new .lrpreviews folder created yesterday by Lightroom itself (because I trashed it to start from scratch) only had Read,Write,Execute for my username but "Staff" and "Everyone" only had read access. Once again this is something I also fixed months ago because my Location of all my Lightroom catalog files and their previews had also been recursively set months ago to RWX for Me,Staff,Everyone.

                               

                              So it appears first of all Lightroom goes creating files and folders but ignoring the hierarchy of permissions completely. Secondly it then goes mental about it because even though my username has read and write access to everything to do with Lightroom it appears there is parts of Lightroom that are trying to do things using the group "Staff" and this is what causes things to go mental.

                               

                              Now for the first time in days, Lightroom is open, it is rendering previews and my fans are not spinning up full speed constantly. So even though Lightroom was "kind of" managing to function it was having serious problems with the .xmp files permissions because it could read but not write back to them because it appears "Staff" requires write access even though Lightroom is running under my user profile.

                               

                              The interesting question here (and I hope someone from Adobe gets alerted to this) is why Lightroom itself created all those .xmp files and chose to not obey the recursive top level of drive permissions I had set months ago?

                               

                              Secondly why does Lightroom not have "some" intelligence built in to detect this very simple issue that there is a permissions problem?

                               

                              This is such old school programming that anyone writing software should be able to do, especially in the modern age. Lightroom should have some kind of decent log system that can show things like this happening by simply detecting that it is having an issue not reading the .xmp file but writing back to it ....... this is such simple basics of programming that I used to do myself 18 years ago in Microsoft Basic, it's called debugging, something goes wrong and you write functions for your app (and users of your app) to tell you what went wrong. For the life of me cannot understand why Adobe cannot seem to do it in this day and age.

                               

                              I am very interested to see if anyone else goes exploring their drives to see if they can see a similar issue with .xmp files permissions or if it just happened to me.

                               

                              I will certainly see how it goes today with editing and if Lightroom behaves now but already this is the first time in weeks that my Macbook is actually cool to the touch and the fans are not going mad.

                               

                              I will report back.

                              • 12. Re: What part of "NO" does Adobe not seem to understand?
                                MKSA Level 1

                                I tested today by creating a new catalog file and importing some photos into it. Catalog was created in the same location where I had already set folder permissions higher up this morning specifying who is the owner and who has which "recursive" rights to the upper level folder containing all catalog files and their previews folders.

                                 

                                Lightroom creates the new catalog file and the lrpreviews folder but ignores the hierarchy of permissions already set higher on the drive. It appears Adobe sets specific permissions on things and they may appear to be ok but in the background (in my world anyway and possibly in other people's too) there is actually permissions issues. Might be an Adobe bug, might also be an Apple bug, neither party is really writing any really reliable software anymore these days.

                                 

                                I haven't had one glitch all day long, been building 12,000 1:1 previews in the background whilst still browsing the catalog and editing images from Lightroom > Photoshop and then back to Lightroom to read whatever metadata changes I did in Photoshop. Fan's only running slightly like they should be when generating previews, not going mad like they have been the past few days. Browsing through the catalog while all this is happening is smooth and functional the way it always should be.

                                 

                                It certainly does appear that "Staff" and "Everyone" must have read & write access to stuff not just read. I hope Adobe can confirm if this is what causes so many issues in Lightroom, simple permissions problems that they are not picking up in their own testing environments. Perhaps this helps other people with strange Lightroom issues.

                                 

                                I will just run a cron job once a day to always make sure permissions are set how I want them to be.

                                 

                                lr-permissions-01.jpg

                                lr-permissions-02.jpg

                                • 13. Re: What part of "NO" does Adobe not seem to understand?
                                  Jao vdL Adobe Community Professional & MVP

                                  Interesting. Did you by any chance recently also upgrade to Sierra? I got all kinds of permissions problems on my RAID drive after that upgrade that only got resolved after I set the owner and permissions of the root level of that drive to the correct (group staff read+write) permissions that somehow had gotten changed during the upgrade. It made a mess of the permissions on that volume. Wasn't a hard fix but still very annoying and I am sure would have completely flummoxed most people. Regarding your observation of Lightroom not inheriting parent permissions on xmp files it writes out that might be an important observation that perhaps would be good to document as a bug report on http://feedback.photoshop.com. You are right that that might be a root cause for the extreme slowness that some experience. This forum is user-to-user and not many Adobe engineers hang out there. on the feedback forum, they do look for bug reports and improvement suggestions.

                                  1 person found this helpful
                                  • 14. Re: What part of "NO" does Adobe not seem to understand?
                                    MKSA Level 1

                                    Hi Jao, not touching Sierra for now, just reload El Capitan about 10 weeks back and have the machine running so perfectly I am loathe to even attempt Sierra, I even avoid any update to El Capitan as everything works OK, so best I leave it as is.

                                     

                                    I will put together something and submit it to Photoshop Feedback and hopefully they can see if they can find the issue.

                                     

                                    Thanks for your help with setting the correct preview size, I think you were on the money about the Retina screen and it's high resolution and my initial previews only being set to 1024. Have managed to render over 22,000 1:1 previews today and managed to keep working all that time ...... so things are looking much better. Thanks again

                                    • 15. Re: What part of "NO" does Adobe not seem to understand?
                                      Jao vdL Adobe Community Professional & MVP

                                      Happy I could help resolve some of the issues

                                      1 person found this helpful
                                      • 16. Re: What part of "NO" does Adobe not seem to understand?
                                        Jim Wilde Level 5

                                        Something to bear in mind when generating 1:1 previews with the settings set to "Never discard" is that "Never" doesn't really mean "Never"....it actually means "never discard unless/until development edits are applied to the image". Whenever you make any develop adjustments to an image its associated preview is discarded from the library cache, because of course the preview no longer matches the image. What happens when making develop adjustments to an image is that the current preview is discarded and a new preview is created which initially contains only the thumbnails to support the navigator and the filmstrip (and this process of creating new previews continues during the edit process). Eventually, when done editing and the image is next brought into view in the Library module the current preview is updated to add the standard-sized preview, but not a 1:1 preview. So if you want to maintain 1:1 previews after an editing session, you'll need to recreate them via the Library menu>Previews function.

                                        • 17. Re: What part of "NO" does Adobe not seem to understand?
                                          MKSA Level 1

                                          Hi Jim, thanks for the reply, I am aware of how that process works. It's just that due to permissions issues with the corresponding sidecar files for a previously edited or even newly edited image, Lightroom could not write back to the .xmp file. This is why when I happened to click on an image that did have previous edits, it then took 3-5 minutes to re-render the 1:1 preview and Lightroom was going out of control. So for me it truly was a simple permissions issue.

                                           

                                          I tested last night taking a collection of about 8000 images whose 1:1 previews I had already rendered earlier in the day. I then made a small edit using the develop module to just one of those 8000 images. I then selected all 8000 and asked Lightroom to build the 1:1 previews for all of them it flew through the 8000 in just a few seconds because, of course, they already existed, and then it just stopped on one (the one I had edited) and built a new preview for it which it did it just a few seconds.

                                           

                                          Jao's suggestion too of upping my initial preview size because of my Retina screen resolution was also "on the money". That in conjunction with fixing the permissions issues seems to have restored me back to a Lightroom I can actually work with once again.

                                           

                                          So hopefully permissions problems is the root cause of a lot of Lightroom issues and perhaps other people wit strange Lightroom or eve Adobe problems in general should go checking their permissions of where their files are located as I have now proven Adobe (or Apple) is ignoring the hierachical permissions.

                                          • 18. Re: What part of "NO" does Adobe not seem to understand?
                                            MKSA Level 1

                                            Hi Jim and Jao

                                             

                                            Lightroom is behaving itself once again after discovering the permissions issue.

                                             

                                            Thanks to Jao I think I have finally found my optimal settings now. Initial previews at 3360 pixels (Auto), quality Medium and then I build only Standard Previews and voila, they are all nice and sharp when zoomed (sharp enough to see if there are any duds) and I don't have to build 1:1 previews at all.

                                             

                                            I have noticed some interesting behavior though which is either by design or maybe a bug.

                                             

                                            I exported 500 images to a new catalog (to test), leaving the files in their original location, opened that new catalog with the above settings (3360/Medium) left it open without scrolling down the library module, and then told Lightroom to render 1:1 previews of all 500 images which it does.

                                             

                                            When that 1:1 preview building is finished I then start scrolling down the library module and regardless that I have just built 1:1 previews of everything Lightroom still shows me grey blocks for all the images until it goes ahead and now starts rendering it's own standard previews.

                                             

                                            So it appears regardless of whether you have built a 1:1 preview Lightroom still builds an additional "standard preview" which is the one shown to you when browsing through library. In my own case it appears I have been wasting a lot of time and resources building 1:1 previews when the above correct settings for standard previews is actually more than ample for my needs.

                                             

                                            I think the naming of "Initial Previews" in the Catalog setting dialog should be named "Standard Previews" for consistency, I think that has been confusing me and perhaps other people who think they need to build a 1:1 preview to be able to view their images clearly and fast.

                                             

                                            Is Lightroom really designed this way, that it ignores 1:1 previews until it has a corresponding standard preview before your library module shows you all your images without grey blocks in places?

                                            • 19. Re: What part of "NO" does Adobe not seem to understand?
                                              Jim Wilde Level 5

                                              MKSA wrote:

                                               

                                              Is Lightroom really designed this way, that it ignores 1:1 previews until it has a corresponding standard preview before your library module shows you all your images without grey blocks in places?

                                              In a word, no. A preview file contains a "pyramid" of differently-sized jpegs, for use in different parts of the UI. Top of the "pyramid" will be either a 1:1 or "standard" sized jpeg, depending of which preview type you have elected to generate. If you don't have existing previews when you open a catalog you'll initially see the grey squares in the grid/filmstrip....if you do nothing you'll see those squares replaced by a correct thumbnail view as the previews will automatically start to be built. If you look closely you'll also see three white dots appear at the top right corner of the thumbnails, which indicate that the standard size preview is being created. This automatic building of the preview "pyramid", with a standard size jpeg at the top, only happens for those images which are visible on screen. Scroll down, and you'll again initially see the grey squares until the automatic preview generation takes place.

                                               

                                              1:1 size "previews" are part of the same preview "pyramid", they are not separate preview files. If you generate 1:1 previews, e.g. on import, the full "pyramid" is created....which includes a standard size jpeg as well. So under normal circumstances, doing the test that you did, when the 1:1 preview generation had completed then when you scrolled down you should not have seen the grey squares. I regularly do timing tests which includes deleting the preview cache  and then rendering 1:1 previews, and I can categorically state that in those circumstances I will never see any grey squares when scrolling down through the grid after the 1:1 preview generation has finished.

                                               

                                              So, given the above, why are you seeing something different? Are you certain that you generated 1:1 previews for all 500 images in the catalog (did you look in the activity centre to see the number of 1:1 previews being built)? Did you have "All Photographs" selected when you initiated the 1:1 build? If you are sure that all 500 1:1s were definitely built then I'm not sure what is going on with your system, all I can say is that what you are seeing is not the behaviour that I typically see or would expect.

                                               

                                              Building 1:1 previews in advance is only useful if you intend to review those images in the Library module while zoomed in to 1:1, e.g. checking sharpness. If in the main Fit or Fill view is adequate for culling, then standard-sized previews would be generally sufficient (provided you have the standard preview size correctly specified, of course).

                                              • 20. Re: What part of "NO" does Adobe not seem to understand?
                                                Jao vdL Adobe Community Professional & MVP

                                                This behavior has changed in one of the more recent version I think. I am pretty sure that it used to be that if you had 1:1 previews, Lightroom would have the whole pyramid and so this was a valid first step in the workflow for some people. This no longer appears to be the case and Lightroom really appears to build only the 1:1 preview which is why I suggested upping the standard size preview to start with. This makes that you generally don't want to generate 1:1 but you do want to have standard previews. I don't know what the reason for this is or whether it is a bug (I would expect the whole pyramid to be generated indeed) or whether this only happens on certain configurations. Bottom line is that it is very important for speed to have standard previews that are large enough and that 1:1 previews don't really help. There are lots of older tutorials that tell you to generate 1:1 so I am sure lots of people fall in this trap and don't get any speed up and loose a lot of time generating the 1:1 files. I generally advise against it.

                                                • 21. Re: What part of "NO" does Adobe not seem to understand?
                                                  Jim Wilde Level 5

                                                  Jao, I do think that the whole "pyramid" is still supposed to be created when rendering 1:1 previews. Running the latest version, I've just repeated the same test and examined the previews.db when the rendering was complete, and that showed 7 levels in the pyramid for all preview files, not just for the images in the grid. So I'm pretty sure that if in some cases the whole pyramid isn't being built, then as you say it's either a bug or a configuration-specific thing.

                                                  • 22. Re: What part of "NO" does Adobe not seem to understand?
                                                    Jao vdL Adobe Community Professional & MVP

                                                    That's what I thought too, but I've seen the same behavior as mentioned above that even with 1:1 previews it will rerender screen-sized previews anyway. Perhaps it is now rendering the rest of the pyramid in the background instead of explicitly right away. There might also be a subtlety when you have the standard preview see set too small where it might discard part of the pyramid now in an effort to clean up and you can end up with a 1:1 preview and only a 1000 pixel preview as the next size but I have no way to back that assertion ;-)

                                                    • 23. Re: What part of "NO" does Adobe not seem to understand?
                                                      johnrellis Most Valuable Participant

                                                      you can end up with a 1:1 preview and only a 1000 pixel preview as the next size but I have no way to back that assertion ;-)

                                                      As of 2.5 years ago, this was the case:

                                                       

                                                      Why Deleting 1:1 Previews In Lightroom Doesn’t Reduce Preview File Size | Lightroom Fanatic

                                                      1:1 previews will not be deleted unless your chosen standard-sized preview is less than half the size of the full-sized preview.

                                                       

                                                      I don't recall seeing anyone testing this since then.