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Session Adjustment Settings Storage Location



  • BeO
    Top Commenter

    ".cos" file.

    You can use any other session (cosessiondb) and visit the "original" session capture/image folder in the library tool, and you see all images adjusted, you can edit them too and it'll be saved in the .cos file.

  • Garry Bondarevich

    Hi BeO. Thanks for your comments.

    The reason for my post was to learn how CO manages files and if it's cleaning up after itself when you perform various tasks. I also want to learn why files appear and what happens when they are deleted if I decide to clean up prior to backing up data.

    I performed an experiment with sessions and found that adjustments are stored in both the session database and the ".cos" files. But, it depends on the "adjustment" since changing the exposure or contrast is stored in both locations while a mask seems to be recorded in the ".cos" file and partially recorded in the sessions database. I don't know the relationships of all possible adjustments between the two locations.

    Here's what I did as a simple experiment.

    1. Start CO and create a new session. Import images to the "Capture Folder".
    2. Wait a couple of minutes and then make a simple adjustment on two images.
    3. Quit CO and check the modified time of the ".cos" files for the two images that were adjusted. They were a couple of minutes newer than the rest of the files. That is correct.
    4. Restart the computer.
    5. Delete the entire "CaptureOne" sub folder in the "Capture Folder" where your imported images reside. This will delete all the ".cos" files and other sub folders.
    6. Start CO and the session will open with all the images loaded properly and the two images that were adjusted in step #2 will have the correct adjustments displayed.
    7. Checking the file structure shows that CO re-created the missing file structure along with all the ".cos" files and thumbnails, etc.
    8. Performed the same experiment as above but this time I added a mask on an adjustment layer for the two adjusted images. After deleting the "CaptureOne" sub folder and restarting CO, the layer reappeared but the mask on the adjustment layer was lost when the ".cos" files were deleted. I was alerted to an error when I started CO the second time.

    This tells me that image adjustments are recorded in both locations and the session database records or maintains only some of the adjustments and relies on the ".cos" files to record adjustments such as masks.

    If you use the "Library Tool" to browse to other folders and view images that have not been imported into the session, then CO creates a "CaptureOne" sub folder in the folder where the images reside along with ".cos" files. If you don't make any adjustments then deleting the "CaptureOne" sub folder is harmless.

    Also, repeated browsing using the "Library Tool" will increase the size of the session database as it records each image that was viewed. The increase in size is probably quite small and you're also left with numerous ".cos" files in each sub folder that you browsed. In the future if I want to browse using the "Library Tool" I will create a test session that I can delete when I'm done.


  • BeO
    Top Commenter

    Possibly the adjustments are stored in the cosessiondb too (in addition to the .cos files) but for me this doesn't matter. As you figured out, any session can be used to browse any image folder, and if the .cos files already exist and contain adjustments these are available in the C1 GUI.

    Except defining "favorites" I usually don't create albums or smart albums in the session (which will probably be stored only in the cosessiondb) so the cosessiondb file is not that relevant to me.

    I don't import images to sessions either.

    The masks are stored in .comask files, same as with a catalog, watch out for them in the Settingsxxx folder.


  • Christian Forrer

    Dear Garry - 

    Thank you so very much for your posting - I was wondering exactly that and was so happy to see, you conducted such as thorough experiment. This info is (from my point of view and appertaining to my workflow) huge.  

    Capture One would be well advised to be very transparent with this information. 

    Case in point : I have set up Adobe Bridge to open Raw Files directly w/ C1. So, I was happily editing pictures after I noticed that I was in the "wrong" Session. I am very strict about 1x Master Folder with 1x cosessiondb-file and 1x CaptureOne Folder. So, in that specific folder I did not yet have a cosessiondb-file. Hence I was looking how to "export" my settings to a new cosessiondb file. 

    If I unterstand your posting correctly, I need only to create a cosessiondb-file in the right folder, and C1 will take care of the rest. That's neat. 

    Thank you again




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