Sync photos using Finder

liah35 wrote: …Sync photos using Finder

Using a cable and Finder to transfer pictures between a Mac and an iPhone is incompatible with iCloud Photos. When you try, you get this:

So you need to choose one method or the other. If you turn off iCloud Photos while you are using Optimize Storage, you may run into some complications. See this:

Understanding iCloud Photos - Apple Community

near the bottom.

You can, however, use the app Image Capture from your Applications folder to transfer picture from the iPhone to the Mac-- but one way only, so this is a transfer, not s synchronization.