Is it possible to automate the "Group into Stack" for photos based on exposure in Lightroom? I'm a huge fan of HDR photos and have a library full of photos that have multiple exposure images used to create HDR images. It would be spectacular if Lightroom could automatically detect sequential photos with an exposure range (E.g. EV -6 to EV +6) and create a stack of them with the EV 0 photo used as the key image. I'm aware of the option for automatic stacking based on time, but this isn't a workable option for HDR photos as some HDR exposures can be several minutes. I'm interested to know how others are managing their HDR photo libraries. I'm using smart folders that exclude any photos that are not EV 0, but I think stacking would be a better option.
LR doesn't have any solid mechanisms for this, unfortunately. LR also lacks some core functionality for letting plugins manipulate stacks, so there is no robust way for plugins to provide this missing functionality. There was a plugin from Rob Cole that did this, but it was limited to Windows and it could be pretty fragile (due to the LR limitations).
Lots of people have asked for much better auto stacking to support HDR and panoramas. Please add your me-too vote and details of what you'd like and why to this feature request in the official Adobe feedback forum: Lightroom: Better auto stacking for bracketing,HDR, and panoramas | Photoshop Family Customer Community . That will make it a little bit more likely Adobe will improve auto stacking sometime before the next ice age.