Lightroom Classic: Auto-stack suddenly inconsistent with Canon 7D

[FeedbackCommunityMember]

I've used Auto-Stack by Capture Time for years with my Canon 7D for HDR bracketed photos. Recently, I auto-stacked a folder of images, and got wildly different results from stack to stack.

I shoot three exposures: 0EV, -2EV, +2EV and that is the order they are taken by the camera.

When I have them in the grid view, before stacking, ordered by capture time, they are in the correct order. After stacking, the stacks are individually out of order, but in an inconsistent way from one stack to the next.

In some stacks, -2EV is at the top, followed by +2EV and then 0EV (completely reversed).
In other stacks, +2EV is at the top, followed by 0EV and then -2EV (rotated by one place).
In some other stacks, the order is correct.

I've unstacked and restacked several times, and the results are inconsistent. Any ideas what I might try to remedy this? I've spent more time re-ordering my auto-stacks than I would have spent stacking the images myself.

Lightroom Classic CC, 8.2 Release
Windows 10 64 bit, 1809, 17763.379
32Gb RAM, i7-6700 3.4Ghz CPU
Canon EOS 7D, shooting raw CR2
Imported to LR Mobile on iPad, and synced to LR Classic CC Desktop

Thanks,
Mike

[Bob Somrak]

Are you the same Michael Hoffman that wrote the Tipsquirrel item about auto stacking?

Did this just start happening after a recent update, maybe 8.2?   I am sure you have tried all kinds of solutions but maybe the magic dust of a preference reset will work.  I am always amazed at what can get messed up with a bad preference file.  You would think Adobe could include code to test the integrity of the preference file.

[Califdan2]

May not be relevant, but was the Grid Sort Order set to Capture time or File Name when you did the Auto Stack?:

[johnrellis]

If you upload a couple sample bracketed groups of three, we can see if the issue occurs in other LR installations or just yours.  Upload to Dropbox or similar and post the sharing link here.

[johnrellis]

"You would think Adobe could include code to test the integrity of the preference file."

I think that the preferences are getting written inconsistently due to an architectural design flaw; see the discussion starting here:
https://feedback.photoshop.com/photoshop_family/topics/reset-your-preferences-moving-from-the-magic-...

Writing an integrity check for that would be hard. 

[johnrellis]

We can also look at the metadata under a microscope to see if there's something suspicious triggering the behavior.

[Bob Somrak]

I remember that thread now John.  Thanks

[SatishT]

Hi Michael,

I have sent you a PM regarding details about this issue. Please share the information to help us debug this issue.

-Satish

[FeedbackCommunityMember]

Hi Robert, yes that was my TipSquirrel post. I've used auto stacking for years. I had thought about preferences but I haven't tampered with anything yet. As far as I can tell, I've never seen this behavior before in LR Classic, so yes, new since the last update. Whether it happened before, I can't say - it's been a few months since I last had a huge folder of bracketed images.

[FeedbackCommunityMember]

Grid sort order was capture time. The files were in the right order before the auto-stack, and if I unstack them, they are returned to the proper order.

[FeedbackCommunityMember]

I'll upload some samples after I do some testing of my own (separate catalog) and respond to SatishT's request below.

[FeedbackCommunityMember]

Thanks, Satish, I am working on the items you requested.

[FeedbackCommunityMember]

I've placed a screen recording of my issue (4 minutes, 24Mb) on Dropbox: https://www.dropbox.com/s/6v5ob29vbxun9mj/LRStackIssue.mp4?dl=0

[FeedbackCommunityMember]

Note that I created a new catalog of 21 bracketed images (the same images in my screen recording above) and I was not able to replicate this in the new catalog. I'm leaning towards a preferences issue, but I have postponed resetting preferences to see if there is anything else to be reviewed first (since I can replicate the issue in my current system state).

[Rikk Flohr: Photography]

It could also be catalog-specific too.  Having the information Satish requested should help us diagnose. 

[FeedbackCommunityMember]

Hi Rikk, as mentioned, I’ve provided a screen recording. But, I’m not able to duplicate the issue in a new catalog with just a few images... so I can’t provide a sample catalog that demonstrates the problem. Those were the two items that Satish requested.

[Rikk Flohr: Photography]

Lightroom Classic 8.3 was released today and contained a fix for this issue. Please update to 8.3 and verify that you are no longer seeing the issue. Thank you!