"Cryptarchs made a crystal that starts fires? Get me one. I don't care how you do it. Go!" —Cayde-6
How's it work? Ha! The underlying principles are quite simple, really. The gun's pyreliophorite crystal— Pyreliophorite? It's an Ionian crystal which bears some resemblance to rudimentary perovskite, which is, as you should know, a crystal with unique photovoltaic properties— Photovoltaic? It means "regarding the conversion of light into electricity." No, no, the gun doesn't create electricity; the gun induces an external combustion reaction. It's perovskite that— I just explained the perovskite! If you'd stop interrupting— Wait. I remember you. You're one of Cayde's Hunters! Get out of here! Shoo! The Cryptarchy wants nothing to do with you!
Sources
Prometheus Lens con be obtained in the following ways:
Xur: Occasionally sells this weapon for 29 Legendary Shards.
Engrams: Occasionally drop from Exotic/Luminous Engrams.
Upgrades
Prometheus Lens can also be upgrades with the following perks:
Column 0
Prismatic Inferno
Fires a Solar trace beam and generates a damaging heat field that grows while the weapon continues to fire.
Column 1
Chambered Compensater
Stable barrel attachment.
Increases stability
Moderately controls recoil
Slightly decreases handling speed
Column 2
Projection Fuse
Distance optimizations.
Increases range
Column 3
Flame Retraction
Kills with this weapon return a fraction of the ammo used to the magazine, extending the beam's duration.
Column 4
Composite Stock
This weapon has a versatile dual-purpose stock.
Slightly increases stability
Slightly increases handling speed
Column 5
Default Ornament
Restores your weapon to its default appearance.
Eye of Osiris
Equip this weapon ornament to change the appearance of Prometheus Lens. Once you get an ornament, it's unlocked on all characters on your account.
Prism
Equip this weapon ornament to change the appearance of Prometheus Lens. Once you get an ornament, it's unlocked on all characters on your account.
Trivia
Prometheus Lens was released with a bug that caused it to be too powerful.[1] In Update 1.1.1, the damage was scaled down too low until a permanent fix can be released, which is scheduled for January 2018.[2]
