[defaultname]

I must be misunderstanding something, however if you plug an iPhone into a Windows PC, the iPhone will ask if you'd like to share photos and videos with the connected device. Say yes and you get a completely typical DCIM share.

[kgwxd]

That used to work everywhere, including Linux, where I want to do the backup, but now it requires iTunes, which I have no other use for and limits the entire process to 2 OSes.

The DCIM folder isn't really standard either, there's magic that happens when you start a transfer to convert the Harry Potter photos to standard photos and, I think, video to mp4. If the device doesn't have enough free space to do those conversions, there is no error message on the PC or device, it just stops mid-transfer (1 hour of my day figuring that one out). There's a setting to not do that conversion, but then you end up backing up files you can't read just anywhere. If it were just my phone, I'd turn off those formats on the phone, but it's my entire families devices.

[defaultname]

Before I wrote my original post, I verified my assumption by connecting my 12P (14.6) to my Windows 10 box (on which zero Apple software runs -- iTunes has never existed on that device). Immediately got the share confirmation and then a DCIM folder.

That folder has the source files in it. HEIC images. MP4 videos (videos, though they are limited to 4GB because of the FAT32 simulation the iPhone is doing). And the other file type for the live photos (I can't recall the extension). No conversions occur, I can copy them directly, etc.

[kgwxd]

OK, so it looks like iTunes is not required on Windows, that assumption came from Apple stating iTunes is required to transfer photos in their docs.

But it doesn't work like that on Linux anymore and I'm certain it used to. There's access to a Documents folder that has folders for things like Keynote, but no DCIM folder. Shotwell works, kind of, but is very prone to failure.

As far as the conversion, do you have the iOS Photos app settings set to not do a conversion? "Automatic" vs "Keep Originals".

This is probably going way off topic, It's not your job to help me troubleshoot :)

[defaultname]

I do have Keep Originals enabled. Forgot all about that setting, but I do believe it tries to be overly clever in Automatic mode (mostly assuming connected devices can't handle HEIC, etc).