Why have an auto sync button?

If I have multiple images selected it should default to auto-sync, if I click on it I could manually still choose what to sync but if there are multiple images selected any changes are auto-sync'd.

At the very least the behavior should be defined in preferences... currently it is so archiac. 

By @phisch777

If that's how you like to work, then just set the button to Auto Sync and leave it that way. You'll find that it says Auto Sync when multiple images are selected, Sync when you've only one selected. That's really the preference.

For years my default way of working is with Auto Sync enabled, and I believe it's the fastest way to work. You just have to keep checking which images are selected, and pay attention to those bezels telling you "exposure updated for x images" (a relatively new feature).

Problems such as described by Johan come when you keep changing between Sync and Auto Sync. Just leave it enabled, and you'll always know that you are adjusting multiple images, if multiple images are selected.

I don't understand why there is a button that shifts between sync and auto-sync, it is the most annoying part of LR for me. If I have multiple images selected it should default to auto-sync, if I click on it I could manually still choose what to sync but if there are multiple images selected any changes are auto-sync'd.

 

At the very least the behavior should be defined in preferences... currently it is so archiac. 

By @phisch777

I love auto-sync, but I would never ever want this to turn itself on automatically whenever I select multiple images. That would be asking for a disaster and would be the biggest mistake that Adobe could make! Search these forums and you will find multiple threads of people asking for help because they deleted scores of edits by leaving auto sync switched on my mistake. If auto sync would be turned on by default as soon as you go to the develop module with multiple images selected, then we would get an avalanche of more threads like that. Maybe auto sync should automatically be cancelled each time you leave the develop module!

If you leave AutoSync on then it automatically applies whenever you have multiple images selected, and does nothing while you have only a single image selected. It would then be up to you to always be alert about whether multiple images are selected.

IMO this button is more provided so that we can suspend the above need for alertness about multiple images selection. Incidentally, there are two AutoSync controls provided not one: one affects Develop and the other independently affects Library. The same selection of images will remain active regardless of switching between these two modules. There may be unstances where we may want to do bulk editing operations in Library, but not to have that happen in Develop - or, the other way around. Our need for alertness then switches away from whether we have got multiple images selected or not, to whether we have got AutoSync active or not in that particular module.

So IMO there is nothing 'archaic' about giving the user the ability to follow their working preference for each of those two contexts, as that perhaps varies with different tasks and circumstances.

AutoSync is such a dangerous setting if it ever applies inadvertently: personally I do like to have its current state exposed. There was some previous discussion here about whether the combination of AutoSync active, and multiple images selected, might need still more prominent notification - e.g. with a change of the cursor pointer too. It's not a safe assumption that everyone will, or should, want to leave this feature turned on routinely.

https://helpx.adobe.com/lightroom-classic/help/develop-module-options.html