Help On My Photo Set Up

IMHO you want the light shining straight down onto the coin surface, not at a right angle.

I never had much success with the iPad mini, for phones or tablets in general the iPhone 4s seems to be the sweet spot (and can be picked up for $20-$40)

Shoot straight down instead of vertically. you will be able to mount/secure the camera much easier.

use a neutral non reflective background (I find black felt works pretty good). and don't be afraid to shoot from a little further distance (your photos are a bit out of focus, you are either too far away, or too close). sweet spot for the iPhone 4s is about 4-5", cant comment on the mini

helps to place the coin on top of a cork so the sensor doesn't focus on the background.

and lastly, remove coin from 2x2

check out the link in my signature, all done with Iphone 4s. while not nearly professional it will get me by for archival/insurance/eBay & sharing purposes

also check out the iphone thread in this section

We all start out the same way, don't fret. Do remove the coin from the holder, and place it on a matte black or dark blue background, to reduce reflections from the holder and setting surfaces. Do move your lights around and experiment, your diffusers are great, now work on the angles and distance.

If you wanted to work up a sliding holder for your phone, that might help a good deal. I've seen one that was just an open wood frame, like a little box without a bottom, that held the phone. The box had an arm that was held at various heights on a 2x4 by two small nails at short intervals, just set the arm on the nails through drilled holes. Worked fine, as far as I could see. He fine-tuned the focus adjusting the height of his coin by stacking Xerox paper until he gets it where he wants.