A good lens only projects what the Laser Diode is outputting.
In the sleds, they use orifices to eliminate fringe projections.
The lens I am using is a very high quality aspheric, and compensated for the BR diode window.
The chinese lenses are the ones, that are "homebrew".
Consistency is nonexistent in the Aixiz lenses.
Power gains may reach 50% of the Hi-Power Lens assembly.
LarryDFW