I have an old cannon digital that I use to take pictures of the entire coin. They turn out ok. I also have a cheap chinese USB microscope to take close ups. They aren't as clear but they work. Your pictures are decent for what you are trying to point out I think.
That was a usb microscope , but for the entire coin I been trying to use my iPhone which doesn't work so well.. Lol
Does it have a macro setting? I would use that. I would imagine that an iphone would have a macro setting and take decent pictures.
There is no simple answer of what camera is "best", or one that will magically allow for the highest quality of photos by simply pressing the shutter release, but your iPhone should be more than sufficient and allow for perfectly acceptable images. It's probably safe to say that any issues you're having are not due to the camera used, but to technique.
I tried using my iPhone 6+ which has a great camera. Even with the macro setting it won't focus on anything more than three inches away. I can't see the details. I bought a clip on macro lens but still can't get good pics. I just use the USB microscope now. It's hard but if I can get the cheap stand that came with it to work I can get a reasonable pic of the whole coin but one side is always more in focus than the other
iPhones are possibly the single best smartphone cameras for imaging coins. Use the highest-available resolution, square the phone to the coin (sitting vertically above it; you can lay it on a box peeking over the edge, as long as it's nice and square) about 5-6" above the coin for best result. Trigger the shutter remotely, either with the timer or an outside trigger method, so you're not touching the phone when the shutter snaps. iPhones will trigger the camera using the Volume button, so if you have earbuds with a Volume control you can use those as a remote trigger.
