Coating of bullets with hex Boron Nitride. Electron microscope photos showing how hBN adheres to bullets after tumbling.
Calculating the Magnification of Objects seen through a Diopter Lens in your Front Sight. I found this chart on the web somewhere, relating lens strength, and distance from lens to eye, to the magnification you get. I cannot find where I got it, so I cannot attribute credit, nor have I done the math to verify it's accuracy, so take it for what it's worth.
Vision test chart. A version of the eye chart used by eye doctors, but adapted for the shooter. If you struggle to see the bottom lines, you need help.
Definition
of Diopter
Notes on
depth of Field
Evident
elevation change due to focus
