Lightroom Classic keeps asking to refine previews for HDR, and then takes forever doing it

[robgendreau]

I've now had a colored pop up come up in Lr Classic 14.01 and ask to "refine previews for HDR to use them in the Library Modue." If I click yes, it proceeds but takes forever...I see a status bar for like a half hour. This has been occurred through multiple starts over a few days since I upgraded to 14.0.

I had problems with LrC crashing recently, apparently unrelated to this, but involving possible corrupt file I created today. I deleted all my previews as a consequence, but then got the popup agains. Even though there's like only about 500MB of previews currently in Previews.lrdata. But it's growing as I watch.

What I wonder is whether if it finds something not "refined" for HDR if it rebuilds ALL the previews for all the files in the library. Or if I should just ignore it. I do use HDR all the time, and I like now being able to see HDR in the Library, but this is kinda nuts.

[JohanElzenga]

If you deleted your previews, then it takes time for Lightroom to rebuild them, no matter if they are HDR or SDR. Depending on the number of previews that have to be rebuilt, half an hour is nothing. Do the math yourself: Let's say that it takes 0.5 seconds to build a preview. Half an hour is 1800 seconds. So in half an hour Lightroom can build 3,600 previews. If your computer is not that fast, or if the images are on a relatively slow drive, then that number is probably very optimistic.

[TDC3000]

I am experiencing the same issue. I think the issue is not "it takes a long time." That part I understand. 

The part that's the problem is that this popup keeps coming up and doing the rebuild. Maybe it's because I've used the new feature to limit the preview cache size. If this is the result of that, then I probably wouldn't use the feature.

In any event, this is an unwelcome repeated request/action given the amount of CPU it consumes. It would be helpful to know what triggers this and what it accomplishes doing this on every HDR image so we can decide what to do with our HDR workflow.

I am not having any crashing issues as the OP mentions.

[JamesRHogg]

I'm having the same problem. There are 18,000 pictures to rebuild. The action bar tells me that I've rebuilt at least 5000 but I still got 18,000 left on occasion it has crashed off after refining 800 pictures. Many of the enhanced Dngs were deleted after processing and producing an enhanced JPG.

What's all this about? And how do I stop it happening? Is it perhaps triggered by the keyword denoised which is automatically put into the DMG's and is also present in my enhanced JPG's. Could I delete all those keywords

[JohanElzenga]

I think this thread is getting very confusing, because the problems discussed here seem to be very different. They may have something in common, but HDR and enhanced DNG are two entirely unrelated things. @JamesRHogg I advise you to start a new thread and explain your problem there. Try to be specific in describing the problem, because 'Enhanced JPG' does not exist and DNG files do not get replaced by JPG files just like that.