Same Thumbnail image for multiple exports from one timeline?

In FCP10.5 and yes, still in 10.5.1, when I use a single project (timeline) and try to export multiple things from it using the range tool, they all have the same thumbnail!  For instance, you carve up an interview into topics, add broll, and export each topic, all clips will have same thumbnail in finder (and where ever you upload it).

The work around I find, is move the part you want to export to the start of the timeline, export that, it will grab a thumbnail from that sequence.  Then move next section to start of project and export. Works but a real pain!

Wondering if anyone else has this issue?

VideoMonkey wrote: ...when I use a single project (timeline) and try to export multiple things from it using the range tool, they all have the same thumbnail!...

I don't think there's a universal standard for how thumbnails are managed in video files. On current MacOS this is apparently handled by the Quick Look system, and the thumbnails are stored in a cache deep within the file system. The cache can be flushed under some conditions. As a Mac app, Finder understands the Quick Look cache and uses the appropriate API calls. There is a Quick Look programming guide for developers who wish to add Quick Look functionality to their apps:  developer.apple.com/library/archive/docu...on/Introduction.html

In terminal there is a command-line interface for Quick Look called qlmanage. See man page for details.

There's an easy procedure using Finder "Get Info" and Quicktime Player to customize the thumbnails show by Finder. See below video.

However I'd be wary of investing a lot of effort in that, because you don't know how those would appear if the video file was copied to another Mac, or a NAS server, much less a Windows machine. Also it appears the thumbnail cache can be flushed under some conditions. The thumbnails would likely regenerate to a default, but your custom thumbnails might be lost.

If you want a visual clip organizer outside of FCP, you might consider Kyno: lesspain.software/kyno/
Maybe others could comment on that.

Instead of organizing clips in the timeline, if you organize them in the Event Browser using keyword collections, those clips can be batch-exported and automatically Finder-tagged using the 3rd-party utility FindrCat:  intelligentassistance.com/findrcat.html

FCP batch export from Event Browser:  larryjordan.com/articles/final-cut-pro-x-10-4-4-batch-export/

How to customize thumbnails using Finder and Quicktime Player: