Need Help Performing A Copy-and-paste For High-magnified Iphone Photos

Hello again, MajorGeeks -- been a while since I needed some assistance with anything. Hope you all can help me here...

Last year, I got a job that requires use of a smartphone for photographs and geolocation. I was between phones at the time, so I borrowed from a relative an old Apple iPhone 7 Plus that wasn't working anymore (turns out it just needed a new battery, which I paid to install to the tune of about $95, but that's another issue).

Now here we are, nearly a year later, and between all the photos taken previously and all the photos I've had to take for work, the 32GB of iPhone storage is almost completely maxed out; in fact, I was briefly unable to access the camera when I was working yesterday. Here's the thing; sometimes this phone doesn't always reinstate disk space whenever I delete a large file (such as a lengthy video), and sometimes, an image file doesn't get deleted at all unless I were to delete files individually one by one instead of doing a mass-select followed by a mass-delete, so there's a good chance that the iPhone storage is just stocked with "ghost files" already removed. There was about 6.5GB of storage space remaining on the phone at the time I'd started using it until about a couple months ago, when I recorded a few videos lasting over 15-30 minutes for a troubleshooting thing for which I needed help on a different matter. I ended up deleting the videos, but still had storage problems until I had to adjust the settings to remove unused apps and delete older messages, just to reclaim some room on the phone.

Now in hopes of reclaiming some more room today (currently have 31.5 of 32GB used), I have been trying to back up my catalog of photos/videos onto external storage, but am having some trouble doing a cut-and-paste on certain photos; I've noticed that photos using higher magnification (zoomed to about 7X or 8X on up) don't copy properly at all, only producing an empty JPG file of 0 bytes. Looking at the info tab on one such photo itself shows the photo having a 4032x3024 resolution with a 324KB file size, but I can't find a way to copy or edit the file to match those dimensions, if not pull the image directly from the phone itself. The photos taken at normal zoom (1X) to medium-high zoom (perhaps around 7X or 8X and below, perhaps as high as 8.5-ish) all seem to be copied just fine, though.

Bear in mind, this phone no longer has a SIM card in it, and any photos of mine aren't backed up on the iCloud either; if anyone has any explanation behind why this type of thing happens with high-magnification iPhone photos, or better yet has any suggestions on how to perform a proper copy-and-paste from the iPhone onto external storage, please feel free to leave a reply. I'll get back to anyone as soon as I am able.


Thanks in advance,
adonisunlimited