I use my scanner but it doesn't work out so much. I tried my phone camera and that doesn't work well. I could borrow a digital camera. I was going to ask what the grade of this coin but I don't think the scan brings out all the detail.
Try it outside of the holder. A scanner can never compete with a camera- even a phone camera- but it can produce adequate results with the coin right on the glass. That millimeter or so of plastic between the glass of the scanner bed and the coin might be what's causing you focus problems there. I used a scanner for years, because it was convenient, and I didn't have to worry about playing with lighting and be concerned about focus (except in circumstances like you have there). I did have a very good scanner, though.
I use the camera in my iPhone XR. I wouldn't say I get professional results, but they're certainly serviceable. The gradient backgrounds are done with another program (remove.bg).
An i or smartphone has a perfectly acceptable camera, and in it's settings function you can adjust the ISO, white balance and brightness before you even take the shot. The two most important things are focussing and light. Choose a solid color background such as white, grey or black to suit the coins composition. Raise the coin slightly on a plastic bottle cap (i use discs of cork), otherwise the camera is trying to focus on the whole image. Raising the coin makes the camera focus on that as the priority. Find something to rest your phone on such as a coffee cup or soup can etc. Try to get as much of the image window filled by the coin in focus without using zoom as this pixellates the image. Experiment with lighting positions till you get the result you are happy with. Set the timer for 2 seconds to eliminate the chance of camera shake.
I do have a better scanner but the one hooked up to my computer comes with my printer. I have problems with small coins the coin comes out weird. There is a lot of extra space and you have to edit it.
I use my cell as it’s all I have. I place it on an upside down glass and it works most of the time. After I take the photos I crop the picture. It takes practice and patience but it works.
How do I take pictures? Poorly! I take such bad pictures that my slabbed graded coins look fake. I have no idea how these guys take such amazing pictures. A tip I got here that really has improved things at least half the time is I have a stack of books, then I put the coin on a plastic bottle cap, make sure I've got good lighting as much as possible and then put my cell phone on top of the book stack so it's nice and steady, and photograph the coin below on the bottle cap. I have a relatively newish iPhone SE (2nd Gen) so the pictures should be great, but the photographer seems to be the issue on my end. I wonder what sort of editing software they use or technique to get those closeup round photos. Anyway, here's an old photo and a brand new one that I took of the same coin with the same iPhone.
You need the phone camera directly over the coin for it to focus correctly. Don’t forget to go to the photos on your phone and crop out all of the background. Pit takes practice.
Get a box or stack of books or something flat and level to put your phone on. Position the camera lens so it hangs over the edge. Then you’ll have the right sort of straight-on angle. I use a box.
You obviously didn't try it like I just said, because the phone is not directly above the coin. When it is, the coin will appear fully round, not showing at an angle like that.