My son and I came up with this today. Used a no-longer working desk lamp, and some stuff laying around. Pics are coming out much clearer.
The only problem with that set up is that you have to push the phone to take the picture. Given the stand is spring jointed, that means there's some minor shifting possible.
Many android camera modules will do better than their native close up, 'flower mode' or macro of sorts with magnifier apps from the playstore. Some get much better control of the focusing than others and some of those apps will also allow voice control. Nice stuff.
You don't although it could be developed into an app/function by manually/touch establishing a focus point then telling it how many x units to focus closer or further. I haven't checked to see if anyone has done it yet. So for now you simply touch the screen where you hope it will focus, then tell it smile, cheese, capture or whatever activates it.
smartphones have bubble level type apps that are amazingly precise zero to surface, then zero when in holding device
They have them good enough, if you can get a qualified surface on your device, to replace the uber-tedious and precise bubble levels that are used to locate things like gantry mills, lathe beds ect. You don't use a Tim Allen Home Improvement Lowes plastic or metal cheapie for that. The sensors on most devices are pretty amazing. And besides, the pix aren't taken dead level, notice what on the same level is and isn't in focus, even on the sharper reverse pix's coin surface. The obverse picture shows the non-level much clearer by looking at the texture and writing on the album. Agree? CAPPED BUST album lettering out of focus, the 1916-17 numbers at the top are crisp.
Put a small pocket mirror in the spot where the coin will be. Maneuver the camera so it "sees" the center of the lens in the center of the shot frame. You will then be plumb, square and level on the coin when you shoot it. This method has the advantage of not caring if either camera or coin stand are perfectly level.
Check out these devices @ http://CamStand.com here is a one for under $50 for photographing coins with your phone: https://photoyourproducts.com/products/cs-mini
OK, here's a couple more. I've been playing around with the lighting, running about grabbing different lights. I'm not capturing the true color of the coin, it's more "golden" than gray. My coppers are appearing darker than in hand.