I save my photos directly from my iPad Pro onto external drives. Before starting, I connect the external drive, and created a folder on that drive named Photos Backup. Here's the steps:
1. In Photos, select the photos you'd like to backup.
2. Tap the share sheet and select Save to Files
3. Select the external drive from the locations list
4. Navigate to the Photos Backup folder
5. Tap Save.
I haven't tried it with > 100 photos in a batch yet, but for the smaller batches it works very quickly. I do use iCloud Photos so for any originals not on my iPad, it has to first download them to the iPad to be able to do the save to Files > external drive.
And of course backing up to an external drive from the iPad works with other files as well. I should mention that I had formatted my external drives to APFS using Disk Utility on a Mac before I sold it. To my knowledge there is not a way to format an external drive with an iPad yet.
If you are going to use your laptop as well, I also agree with
@AndyMacAndMic that backing up your iOS devices to your laptop is OK as an
interim step, but you'd want to regularly backup your laptop using multiple methods as mentioned.
That’s a lot of manual steps. Backups should be as automatic as possible. But more importantly, whole backups include more than photos and a few other files. Whole backups are for every file, every app, all app data, every setting, the whole system—so that with one restore you can be back up and running.
Also I assume OP is backing up the entire laptop to some external drive, so the iOS device backups aren’t existing only on the laptop.
OP, I back up my iPhone and iPad to iTunes, and I used to point iTunes to a folder on an external drive, but sorry it was a long time ago and my memory is a bit fuzzy. For what it’s worth, I don’t remember it acting funny, but I did eventually switch back to using the default internal drive iTunes folder just to be safe in general. One issue is that sometimes my external drives get randomly disconnected from macOS, then iTunes is unable to find its folder. Annoying to have to reconnect, but not the end of the world, unless one never checks the screen and assumes a device is automatically backing up when it’s actually not.
iTunes shouldn’t be backing up iTunes media from your devices since those already exist in the iTunes library, but a big camera roll can definitely create big backups. Sorry, I can’t definitively answer your question but my feeling is it’s probably fine. If you can’t find a good answer and are uncomfortable trying it out, you’re probably aware of your other options, which are:
- store all or the bulk of your photos off device on a cloud service (I believe iCloud photos can automatically offload photos after a certain capacity is reached; but of course you have to pay monthly)
- upgrade your laptop’s internal storage
- backup to iCloud? (not sure if this includes camera roll, and of course monthly fee if your backups are big)
I don’t know if this works on PC, but on Mac I believe there is another option where you keep your photos in the computer’s photo library application (Photos on Mac) and sync them to your devices via iTunes, which then shouldn’t include the photos in the backups since iTunes knows they’re already in the computer. But it sounds like you have or will have more photos than will fit in your laptop.
On an unrelated but kind of related note, iOS devices really need a better backup system in place where you can make versioned backups and browse/restore individual data and apps like in Mac’s Time Machine backup application. You can get around the lack of versioning by backing up your iTunes backups to Time Machine. But there’s still no browsing inside iOS backups, so you have to guess which backup you need and restore the entire backup, extract any data if you can, then revert back to the most current backup. It’s a complicated process with limited probable success. Rant over.
Hope you get everything worked out.
