Lenses for 445nm or 473nm

[Krane]

hey all, Im a noob, what kind of lens would you use to focus the beam, this is one of those "i don't have it yet but i need to know" questions, so thing number one, what kind of lens you use? is it the convex lens that is plain on the other side?? that's the only one that makes sense to use, and another question, if focusing u can create a 1mm wide beam for example 4 feet away, how would you focus it to "infinity" and is it possible, what i mean by infinity is like when u use binoculars, when u focus them on a far object you can look at objects that are even further but they will not need focusing anymore... so what is the max possible viewing distance i could get from a 1W 445nm, and handheld 473nm of the max power i could build/buy for under $250 that will be discussed separately.

 

[ZRaffleticket]

for 445's you want 3 element glass lenses or 405-G1 or 405-G2 glass lenses. Focusing to infinity has the dot as small as you can for as long as you can-- every laser is different. I'll tell you that you won't be getting any 1mm beam from a 473 or especially a 445. Distance isn't really something you want a 445 or a 473 for; best bet is a greenie (532nm) for that.

For 473nm; going DIY is extremely difficult. Mine cost me about $550, and less power would only be about $100 less in the big picture. Not sure if eytyxhs is still selling his 473nm pointer; check the B/S/T section every now and then. Otherwise expect the $300 - $350 range for a 473nm pointer.

 

[Krane]

thanks for your reply! I know that green is most visible to human eye, but i kind of got bored of green when i owned it for 3 weeks, blue is more rare color... thats why I wanted to compensate with the power of 1.3+watt power, it should make the beam look less indigo and more blue and hence much more visible.

I feel like low powered (5-10mW) 445 will look identical to 405nm that is 1W, it might not be true, but its what i can tell from the pictures everywhere.. Anyway back to the topic, you say that DIY the 405 is expensive.. Ill have to agree $500 is pretty expensive, though do you think the prices may fall in a couple of years? the sky blue color is visible bright and just looks amazing.. Looks like ill have to go with high powered 445nm for now..

 

[ZRaffleticket]

Well; there's some things you should be familiar with before making your decision:

Pictures aren't nearly the same as the human eye: Cameras don't pick up colors correctly for the most part, and it's really difficult to compare two high powered lasers of a similar wavelength.

I can guarantee a 600mW 450nm laser will be blue; and a 1600mW 450nm laser will be blue. It's the wavelength that has all to do with that, power only affects brightness (and burning)

A low powered 450nm will not look like a high powered 405nm. I said DIY'ing a 473nm will be very difficult; DIY'ing a 450nm or a 405nm will be very easy in comparison.

Edit: missed that last part; I DOUBT prices will fall lower on 473's than they are right now. The only practical use for these anymore are the good beam specs. Right now I *think* this is still for sale http://laserpointerforums.com/f39/fs-cni-glp-473nm-10mw-74745.html

 

[Krane]

yes exactly, power makes it brighter, and if you add BRIGHTNESS to BLUE it will look something like this:
Blue Haze Blue Haze Blue
Blue Haze DOT Blue Haze
Blue Haze Blue Haze Blue

It's pretty good I gotta admit, but imagine if you had a 473nm, if you got your hands on 1W+ the dot would probably look white with sky blue haze like this:
Sky Haze Sky Haze Sky
Sky Haze DOT Sky Haze
Sky Haze Sky Haze Sky
(I know i used cyan instead of sky blue but you get the idea)

 

[Bionic-Badger]

No.

You don't seem to understand how color mixing works. You don't just add "brightness" to make white or any other color. You have to mix colors to make light look white. White is just the "hue" your eyes interpret from a mixing of three different color tristimuli. In other words your eyes see red, blue, and green, and the mix of those determines the final color your brain sees.

Adding blue light to blue light will produce more blue light. Adding cyan to blue light will still look bluish, not white. If you want something that approaches white, you need colors that excite the other tristimuli in your eyes, like combining blue with yellow.

Don't judge what you've seen in photos as what your eyes will see. The camera uses a Bayer array to filter out colors that get interpreted by the CCD/CMOS chip. The chip itself only sees light intensity--including infrared and UV. By filtering out certain colors it only sees the intensity of a specific color at that spot. When the camera is photographing something extremely bright like a laser spot, sometimes the intensity is so great that even the camera's color filters aren't sufficient to block the light; all three color channels (RGB) see the light and the resulting pixel looks white. You can see this effect with your own green laser pointer and a digital camera.

Your eyes are not CCD cameras with filters. They see light in a different way that takes effort to capture in a photo.

 

[ZRaffleticket]

Thank you for that explanation ^
Just because a camera sees it one way doesn't mean eyes do. Heck my good camera (18 megapixels) sees 473nm as indigo...

 

[Krane]

noooo

i understand how color mixing works im a biology major, you dont seem to understand what i mean, cameras have nothing to do with this, i used to have a green laser and being close to it on the wall the dot would appear white, as well as when i was little and stupid and was playing with 1-5mW lasers with dying batteries i shone it inside my eye, and i saw white in a couple of seconds.

What happens is in our eye there are cones and rods, cones see color, rods see black and white and are used at night, there are specific cones for 3 prime colors, the sodium channels that constantly pump sodium to your eyes in order to allow you see things, it takes ~45 seconds to replenish the sodium levels when you're looking at a bright object of specific prime color for too long, so if u stare at a red laser spot, your eye wont be able to perceive red anymore and will see it as white, but when you close your eyes you will see the opposite of red which is CYAN, (concept of 3D glasses that are red and opposite)

So of course it will not turn into white, but at least that's how it will appear to people in close proximities..

And here's something I found on wikipedia, basically what i said only without explanation of course, wow i just realized how basic wikipedia is... didnt seem that way when i was in HS lol.
"White light can be generated in many ways. The sun is such a source, electric incandescence is another. Modern light sources are fluorescent lamps and light-emitting diodes. An object whose surface reflects back most of the light it receives and does not alter its color will appear white, unless it has very high specular reflection [mirror effect]."

 

[ZRaffleticket]

Somehow slipped my subscriptions, 445nm will not look like 473nm no matter what you do to it. You shouldn't be viewing a 100mW laser at a very close distance yet alone a 1300mW laser at a close distance. Brightness won't make it 445nm look like light blue, trust me. Unless you want to get very technical and include how our brains comprehend colors.

 

[Krane]

well exactly, our inability to process colors, too bright works in our, at least mine, advantage lol

 

[IsaacT]

If you want to continue viewing colors, don't stare at powerful laser's dots. If your eye is being so overloaded with light that your brain is making it look white because there is too much light then guess what? You are probably damaging your eyes. Just my 2 cents, do what you want.

 

[TheDukeAnumber1]

i used to have a green laser and being close to it on the wall the dot would appear white, as well as when i was little and stupid and was playing with 1-5mW lasers with dying batteries i shone it inside my eye, and i saw white in a couple of seconds.

You are literally flash blinding yourself. That's very bad for your eyes. Please be more careful.