I am waiting for some beam expanders I have ordered to arrive and was just testing spot size at 50 - 70 feet, the good old 7875 is still a solid diode and looks like about a 10 x 50mm bar at 50 feet so with a 10x expander it should focus to a 1 x 5mm bar in theory ?
Anyway I can see the spot on a leaf and my laser is securely clamped down, but when looking through binoculars it looks as if the lasers spot/bar is floating out in the air a foot ahead of the leaf, no there's no spider web or branch, I walked out and checked that the spot is on the leaf very slowly making a brown rectangle on the leaf, but through the binoculars it has a holographic effect.
I know this is to do with the mechanics of light and lenses but this holographic type effect is inspiring to see first hand.
ALWAYS PROTECT YOUR EYES, IF YOU ARE NOT SURE IT'S SAFE THEN WEAR YOUR LASER SAFETY GLASSES THAT ATTENUATE THE WAVELENGTH YOU ARE WORKING WITH.
Anyway I can see the spot on a leaf and my laser is securely clamped down, but when looking through binoculars it looks as if the lasers spot/bar is floating out in the air a foot ahead of the leaf, no there's no spider web or branch, I walked out and checked that the spot is on the leaf very slowly making a brown rectangle on the leaf, but through the binoculars it has a holographic effect.
I know this is to do with the mechanics of light and lenses but this holographic type effect is inspiring to see first hand.
ALWAYS PROTECT YOUR EYES, IF YOU ARE NOT SURE IT'S SAFE THEN WEAR YOUR LASER SAFETY GLASSES THAT ATTENUATE THE WAVELENGTH YOU ARE WORKING WITH.