My son-in-law came up with the idea to use the loop/lens in conjunction with the camera, but he never said how he did it.
I just used the 'trial and error' method, focusing in different ways (thank goodness for digital),
I found that if I had three hands it would have been easier, but after a few dozen tries I learned that focusing on the magnifying lens worked the best.
Look through the loop, moving it forward or backward until the image looks large and clear enough, then bring the camera to about 5 -6 inches focusing on the loop.
If I had...something like a goose neck illuminated magnifier or one of the tools called 'third hand', catching the images would have been a bit easier. I think the illuminated magnifier would be good because my trial and error method had a ton of shots that were not lighted all that well.
Of course, this whole hack is not needed if one buys a really, really good camera but I make to with what I have on hand.