Get the best focus for your laser using a mirror camera Canon 1100 or 70D.
How does the laser beam focusing works?!
Comparing a different lens: 2 types of 3 element lens (black), G2 lens (golden), G7 lens (golding with a bigger glass)
Test one – regular 3 element lens
Focal range: 63-67 mm from the aluminum housing to the surface
Laser beam spot size: 85×130 microns (uM) (highest laser power density)
Original images
Test two – regular 3 element lens (longer version)
Focal range: 63-67 mm from the aluminum housing to the surface
Laser beam spot size: 85×130 microns (uM) (highest laser power density)
Test three – G2 lens
Focal range: 32-33mm from the aluminum housing to the surface
Laser beam spot size: 65×130 microns (uM) (highest laser power density)
Original images
Test fourth- G7 lens
Focal range: 83-85 mm from the aluminum housing to the surface
Laser beam spot size: 85×130 microns (uM) (highest laser power density)
Original images
Interesting laser beam calculator
Focal range laser lens test. laser lenses tests (PDF). Testing lenses from different optical producers.
Improved laser beam quality
Laser beam spot improvement for 445 nm diode laser (success – new laser beam spot)