HEIC photos on iPhone show as new items in Photos import window

Hi

The problem is the conversion. Photos will only recognise them as duplicates if the file is exactly the same. When HEIC/HEVC is converted on download, it is no longer the same file.

The only solution is to manually choose what to download (only new photos), or to stop the conversion happening (on phone - settings>photos>transfer to PC>keep original). This will become less of a problem when you start using iCloud since the two libraries will be synced exactly.

Obviously this won't help for the images already downloaded. For these you could choose to delete the converted files on your mac for those where HE format is still on the phone, or to delete the unconverted ones on your phone, then sync the converted ones back to the phone from the mac.

Your last option is to wait until you've synced with iCloud, and then use one of the two (suggested round here) apps for removing the duplicates. (Power photos or photo sweeper)

I hate the idea of an external drive. The whole concept of the iMac is that it's a clean machine with no extraneous devices and wires. Every time I try to use a portable external drive, I lose track of what it's for because I have a few old ones lying around! But that's just me... (oh, I see you recommended a thumb drive. Would that really work?)

You need to have at least one external drive connected at all times anyway, or how are you making regular backups of your Mac? The easiest backup would be Time Machine to an external volume. As your iMac is sitting on a desk and not carried around like a laptop, it is no hardship to connect a few external drives. My external drives are labelled and sitting on a shelf behind the Mac, and the cables are also labelled, so I can see it a glance, which cable belongs to which drive.

The "Optimise Mac Storage" will help you to keep the local copy of the iCloud Photos Library small, but it will make it much harder to make regular backups of your Photos. You will still need to create regular backups of your Photos Library, but Time Machine will no longer be able to backup all high resolution originals. It is easier to have only a small iCloud Library and that does not need "Optimise" and to keep the full archive with all photos on an external volume.

An alternative would be to split your Photos Library - a smaller library for iCloud Photos (not optimized) and a full archive of all photos on an external volume. You can have many Photos Library, but only one of them, the System photos Library, can sync with iCloud and is available in the Media Browser for other applications.

My iCloud Photos Library is holding only my Favourites plus the new photos I am currently working on. This library is accessible on all my Macs, my iPhone, my iPad. I am regularly copying all new photos and videos in to my archive photo libraries on my archive drive with all my photos, videos, music. This archive drive is backed up to a second drive by cloning it with Carbon Copy Cloner. The Mac itself is backed up to Time Machine. I am rarely needing to access the archive drives with the full libraries. For most purposes the smaller iCloud Photos Library suffices.

There is really no significant benefit to having the jpg files on the mac. If you need a jpg version of a particular image, you can export it as jpg in a few seconds, then delete the exported jpg when no longer needed.

I have a folder on my desktop that I export to when needed, and then purge it every month or so. Plus it is becoming less and less necessary as more websites start to accept HEIC directly (Eg facebook) or convert them automatically when chosen from photos (eg mac mail).

It is certainly a lot less hassle than manually selecting files to import evey time you take new photos.

bareiff wrote:

I am still using High Sierra, about to change to Big Sur on new iMac. Also, about to start using iCloud photos to get my photos off of the new smaller SSD drive.

You do know that iCloud Library is a syncing service and not an off computer storage facility. To save space on your computer you'll need to select "Optimize Mac Storage" and that only kicks in when you have about 20 GB of free space remaining. However, this user tip can help you optimize the library more completely: How to force Photos for Mac to Optimise the Storage Immediately - Apple Community

Any time you want to use a photo outside of the library, i.e. print, email, in a project, you'll have to wait until the full sized version is downloaded to the local library before proceeding.

You might want to consider getting a small, external SSD to store and run your Photos library from. This one from OWC is an excellent choice and is small enough to be easily carried with a laptop: OWC Envoy Pro mini - best for laptops.

Just some food for thought.

Dropbox is not capable of storing or syncing a Photos library safely.

That is not a (conventional) thumbdrive. It is a full spec SSD, just in a small thumb drive style housing.