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More Purple Than Blue

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A better word would be Cobalt Blue. My favorite color.

 

DrSid

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Good word .. but at least on the picture, it totally is not the color of 445nm as I see it. There is lot of violet tones in it. But then it is hard to compare glass object and light.
 
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Yeah it was just to reference the violet/blue color. Obviously everyone's interpretation of the levels of each is different. And you're right, you cant compare glass to photons.
 

Gappa

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To me the dot looks almost white with the naked eye but I do sense violet undertones too.
 

Benm

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Royal blue is a nice description of the color. Lumileds/luxeon used the same term for leds around this color too.

445 is on the violet end of what is considered blue in general speech - but if you ask someone with zero experience in lasers they'd say 445 is blue. Perhaps the problem is with laser lovers that are more used to 473 being 'blue', despite that color might be interpreted as 'cyan' to the general audience.
 

weeba2kv

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The beam and the reflected light looks violet/blue , but the dot itself is pure true blue -with the eye in real life , not on pics and video's -
On photo's and video's the reflected light and the beam looks blue just as the dot !
Correct me if i am wrong...
 
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Svensson

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The beam and the reflected light looks violet/blue , but the dot itself is pure true blue -with the eye in real life , not on pics and video's -
On photo's and video's the reflected light and the beam looks blue just as the dot !
Correct me if i am wrong...
That's exactly how I see it.
 

Traveller

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It all depends on white balance which your camera calibrates upon exposure. Most probably use auto white balance...It's easily correctable in any photo editing program...which I find reflects my perception of 445nm well...
The color heavily relies on one's perception of, particularly in the near-ultra-violet ranges (as nicely described by our local Professor).

In terms of photographing the beam / dot / bar, the camera's sensor has it's own form of perception. Most sensors try to emulate the human eye by concentrating on green. This is achieved by adding extra green filters, giving you GRGB or RGGB (assuming a Bayer filter is in use).

Finally, auto-white balance (or even post-correction) is rather difficult when an image has no pure white (or at the very least, pure black, but there's no guarantee). I used a Kodak Grey Card to take one of the two images below, but the results were the exact opposite from my perception (which is rather towards the blue end, particularly when views next to a 405nm beam). Just look at the hosts; the fact that manual white balance was correct should be immediately evident... ;)



 
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mikeeey

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I think it really depends on the power of the 445nm.
Humansymphony's DIY build had more of a purple look to it (especially the beam) (ouput unknown)
My Arctic had a somewhat similar appearance to his. (between 700 - 800mW)
My Spartan looks VERY blue (even the beam), I was shocked when I first turned it on. (+1W) Or could it be that mine is....well... 447nm?:rolleyes:
 
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X FLY

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I think it really depends on the power of the 445nm.
Humansymphony's DIY build had more of a purple look to it (especially the beam) (ouput unknown)
My Arctic had a somewhat similar appearance to his. (between 700 - 800mW)
My Spartan looks VERY blue (even the beam), I was shocked when I first turned it on. (+1W) Or could it be that mine is....well... 447nm?:rolleyes:
My spartan also is a nice deep blue. Maybe the few extra nm on the spartan make it "pure blue"? :) And it is possible that the spartans use a slighty different 445nm (447nm) diode because CNI uses brand new diodes (not diodes harvested from 130 or 140 projectors).
 

X FLY

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is this blue ? or violet ( my first pic of my 445 ) and it's true blue to me



ps: i posted a few pics in multimedia ( first pics )
The glow on the bed looks violet/blue to me maybe a little more violet.
 

The_LED_Museum

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When I blast mine at a white ceiling in a darkened room, the room itself appears to be illuminated with a deep blue color -- with no real hint of what I'd call "violet".

And I might add that I spectrographically measured the wavelength at 441.40nm with the unit (an Arctic) set to "high".
 
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I said maybe :) Someone should ask CNI what diodes they use.
As far as I know, they all use the same diode. I believe there are other diodes, but the cost is to high to add to a $200 pointer. The Chinese cant even get the diodes in China. They have to order them from the US, and other countries.
 




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