Hi Todd,
Photos attached.
#1 All mounted to camera via step rings. The tubes were from a past purchase where the genius was with the steel “donut” at the final screw element. Originally, a magnetic translucent disk with a 35mm silde cutout attached to the donut; just point to a light source and shoot—shutter speed pretty irrelevant. I am using magnet to attach various film adapters to the donut. Some adapters are rom the “Wolverine” crappy scanner—the scanner is crap, but the adapters are great. I use a 50mm macro lens so the included tubes to the job fine; a 100mm macro may require more tubes.
#2 Shows how the (strong, rare earth disc) magnets attach to the donut.
#3 Shows the tube assembly off the camera (and, therefore, how some other tube assembly might be able to work; coming up with the steel donut might take some scrounging around), and how the magnets are attached to the aps adapter. Note that the magnets attach on two different planes so leveling the magnets must happen somehow. I used two different depth magnets which seems to level the planes very well. The grip tape on the magnets keep the adapters from sliding/shifting on the donut.
#4 Shows two additional adapters I use. The 35mm slide adapter allow for slide passthrough so that shooting doesn’t have to slow down. The 35mm negative adapter also allows passthrough. Note that the white on the ends is non-scratch material to keep the film from touching the plastic adapter AND to keep the film taught so it doesn’t drift around in the adapter. I had to sand/file some of the mouth and tail of the path to allow for the white material to be mounted (two-sided tape) on the inside to allow for film movement through the adapter.