How visible do you see 405nm ?

[Benm]

I find it a bit tricky to see... not so much that i can see a beam is there and such, but when the dot hits some non-fluorescent surface it always seems to be out of focus. I suppose this is logical since it's on the fringe of the visible spectrum and when your eyes focus on the rest of the wall or whatever it hits, chromatic aberration makes 405 nm light unfocused on the retina.

Despite the logical explanation i think the effect is a bit eerie - looks like "it's not quite there" to me.

 

[Emialias]

I find it a bit tricky to see... not so much that i can see a beam is there and such, but when the dot hits some non-fluorescent surface it always seems to be out of focus. I suppose this is logical since it's on the fringe of the visible spectrum and when your eyes focus on the rest of the wall or whatever it hits, chromatic aberration makes 405 nm light unfocused on the retina.

Despite the logical explanation i think the effect is a bit eerie - looks like "it's not quite there" to me.

im pretty sure it has something to do with how the human eye evolved to be able to focus in a certain wavelength range, and Near UV is not often encountered if at all in normal every day life outside of lasers.
i might be wrong, but theres nothing wrong with guessing... is there?

 

[T_Warne]

I have trouble seeing the beam unless it is dark and the room is smokey. The dot, unless looking through protective eyewear, always looks like a large shimmering purple starburst.

 

[paul1598419]

It really depends on the power density of the beam. I can see the beam from a 700 mW or higher 405nm laser as long as I am looking down the axis of transmission. Lower powers like 100 mW I can't see the beam at all and the dot is faint.

 

[Skittles]

I have trouble seeing the beam unless it is dark and the room is smokey. The dot, unless looking through protective eyewear, always looks like a large shimmering purple starburst.

The dot looks like a snowflake to me. I can see my 85mw beam very well in the dark and slightly in a well lit room.

 

[paul1598419]

Give it 40 to 50 years and tell us what it looks like. Most people in their youth can see UV and IR much better than us senior citizens can. :crackup:

 

[Skittles]

Give it 40 to 50 years and tell us what it looks like. Most people in their youth can see UV and IR much better than us senior citizens can. :crackup:

Time to check out IR lasers before its too late. :crackup:

 

[dressur4]

My problem is that I will need glasses for distance. but i can still see the IR coming from my remote it flashes, and the IR outputs from security cameras Can you pump a dye laser from a bank of high powewred 405nm modules?

 

[Benm]

im pretty sure it has something to do with how the human eye evolved to be able to focus in a certain wavelength range, and Near UV is not often encountered if at all in normal every day life outside of lasers.
i might be wrong, but theres nothing wrong with guessing... is there?

I think you're correct. The human eye performs best in the orange to cyan range, with the far red and blue areas still visible but not that brightly or accurately.

As for the "IR" leds on security cams: on some models i can see them, on other i can't. Things like TV remotes are too deep into the IR for me to see at all, perhaps unless i stick the led right up to my eye in a dark room. This is -not- a good idea though, those led's emit a lot of optical power. While not a laser, it'd be as stupid as getting the brightest green 5mm led and looking straight into that.

Interesting someone mentioned age though: does the range of wavelengths you can see change with the years? Or is is just general loss of visual acuity?

 

[dressur4]

Probably cataracts. My Mom had cataracts and had surgery she said it was like she had the vision of a teenager. Cataracts I'm sure filter those wavelengths. Age causes cataracts.

 

[Gazen]

To me, my 200mW 405nm pocket’s beam is very visible from the holder at night, and faint inside in a somewhat dimly lit room.

On the other hand, the dot always appears out of focus, as others as observed, and is only visible for a few meters in broad daylight.

 

[paul1598419]

If you can see the beam at all from a 405nm 200 mW laser in broad daylight, your sight is much better than most. I doubt I could see the dot in sunlight at 20 meters.

 

[Mosc007]

My 900mw pointer is quite dangerous at 405nm.

The Beam is not easy for me to see. Even the spot is not very bright. It's only when smoke comes from the target I remember how destructive 405nm is. You need to be very carefull with this wavelength.

That one is not in my Signature. It's in an S4 Host.