VG-LX7 Focal Point

Looking for advice from anyone owning a VG-LX7 system.

The manual says: The recommended distance from laser outlet to materials is
3-10cm. Out of range may be out of focus.

  1. Where is the laser output measured from?
  • The bottom of the lens
  • The bottom of the laser’s body before the lens
  1. The focal point 3 -10 CM (1.181 - 3.93") - seems very broad range and far from the head. What distance are you using to image?

I was under the impression that these units focal point was synonymous with the bottom of the frame?

The only true way to focus a diode laser is to visually focus it. You activate the laser at its lowest possible setting and then adjust height and lens for the clearest visual on the laser spot/square.

Maybe answering my own questions:

Learned that:
There are 4 common types of diode laser lenses:

  • 3 element
  • G2
  • G7
  • G8

The G8 has these specs:

  • Optimal focal range: 30-100 mm
  • EFL: 8mm
  • NA: .2
  • Best focal range 70-75 mm
  • Smallest laser beam spot: 77 x 130 microns (0.0030315 x 0.00511811")

Mistake in the manual???
If you assume the VG-L7X manual had the wrong units for focus, i.e CM vs MM.
Then I have a G8 lens in my unit? Is this a coincidence?

The smallest beam spot also explains why the dot looks rectangular ( laser diodes do not operate in TEM00).