Hi colleagues. It's hard to find where to post/send suggestions for feature updates :-) I'm using LR Classic for merging HDR DNGs from multiple RAW files (for commercial interior photography, landscape photography etc.) and current tools consume to much of my time for simple tasks. It's not a question of engine performance - it's a question of how it works. Let me explain in detail:
1) Auto Stack by Capture Time - does not work well because the total exposure time may vary greatly and "Time between stacks" isn't reliable for stacking because of it. It can take the camera 1 second or even less to capture all 5 frames in a 3EV bracketing (1/8000s + 1/1000s + 1/125s + 1/15s + 1/2s), or it can take 90 seconds and more when I do bracketing in low light, while shooting evening landscape or interior using low ISO. With current version of LR Classic I can't simply ask the app to "stack HDR exposures" and need to do it by myself, losing tons of time. I think a feature like "Auto Stack by time between captures" needs to be added and it has to use the time it took the camera to do the capture based on EXIF data. If the time was <1s (including exposure time in EXIF) than it means the photographer used HDR mode or continuous drive mode. I mean that if the 1st frame was taken on 18:55:01 (1/125s) next one on 18:55:01 (1/15s), next one on 18:55:02 (1/2s), next one on 18:55:03 (4s) and the last one on 18:56:07 (60s) they all need to stack together because it was one HDR 5x3EV capture. The LR engine has to include exposure time together with time between captures for stacking. This also definitely will help when stacking reportage photos when I used fast continuous drive mode like 10-20-30-60FPS on my Sony A7R3 and A9 or my Olympus EM-1 Mark II and there can be more improvements in future LR versions for reportage photographers to help them faster cull series.
2) HDR merging - I often use the Ctrl+Shift+H shortcut to merge a stack to HDR. The problem is that there is no delayed queue and the merging process starts immediately. This slows even my powerful desktop PC, and on my MacBook Pro results a great slowdown. Right now I do need to select every stack by myself and press the shortcut to start merging - when the CPU is overloaded with merging even the selection with the mouse works really slow, and I have to spend lot of time simply sitting with the computer and pressing, pressing and pressing the shortcut, waiting few seconds every time because the system is overloaded with calculations. My idea is that it would be great to have an option to add all merges to a queue and later execute it when I do not need my computer. Also an option "Merge all stacks to HDR" would be great. This also applies to panorama merging - batch/queue and sending all stacks to merging will improve photographers performance. For most of photographers merging a lot of work into a big batch, starting it and leaving a computer calculating for few hours is better then siting in front of the display with sluggish interface when the computer is overloaded with rendering.
P.S. Options like "Automatically create Smart Preview for merged photos" and "Automatically create 1:1 preview for merged photos" would be great too.
BTW, most things in LR could benefit from a batch/queue feature. If somebody in Adobe is interested in a feedback from users who use LR for working with hundreds of thousands of photos every month you can contact me for detailed explanation :-)