What happens if the battery fails?
To repeat: you’re always protected from damaging UV/IR radiation. And no matter what, your eyes are always shaded from flash. When you pick up an OFF Speedglas filter, it’s intermediately-shaded. When you turn on the filter, it “lightens” and becomes transparent. When an arc is struck, the filter darkens. (The dark shade level depends upon which Speedglas model is used.
