EpicHam
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405nm lasers are from blu-ray players, 445nm is from projectors.
my bad
FIXED
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405nm lasers are from blu-ray players, 445nm is from projectors.
405nm is very VIOLET to me..., it doesnt look blue to me at all. I love my 445nm, and i probably like it more than 473nm. I think my favourite colour of laser is AMBER/589nm
405nm is one of the three cheap colors (the other two being 532nm and 650nm). 405nm is cheap because it is used in Blu-Ray Disc. The color of 405nm is far violet. The most widely cited dividing line between violet and ultraviolet is 400nm, although some authorities draw the line at 380nm. The only reason anyone calls it "blue" is because of the registered trade-mark "Blu-Ray Disc," a name they picked because it sounded good, reminding people of "true blue," as opposed to "violet," which reminds people of pansies and daffodils. Sellers of 405nm lasers sometimes characterize the color as "gypsophila," a type of flower that includes the variety known as Baby's Breath. 405nm lasers can induce fluorescence nearly as well as a black light. You need a lot more power on 405nm to achieve the same apparent brightness due to the limitations of the human eye.
447nm (also known as 445nm or 450nm) is somewhat more expensive, but very reasonable in higher wattages. This color is usually known as indigo or royal blue. Isaac Newton was the one who added indigo to the six colors of the rainbow, making seven colors (because of his interest in alchemy). Indigo is a plant dye, the exact color which can vary depending on how it's processed. Several varieties of indigo are used in art as color names, no two quite the same. Some authorities define indigo as 446nm to 466nm, others as 430nm to 450nm. 447nm is one of the few wavelengths that falls within everyone's definition of indigo. Without indigo, 450nm is the most common dividing line between blue and violet. In the East Mediterranean and the Byzantine Empire purple was the color or royalty. Western Europeans thus adjusted the blue they used to signify royalty by making it as close to violet as possible and still blue. Thus royal blue and indigo could both be considered correct for 447nm. People who sell lasers just call it blue.
473nm is commonly known as "sky blue." The actual color of the sky is impossible to accurately characterize (too many variables) but 473nm is a reasonable approximation. In the world of lasers this wavelength is known as "true blue" to distinguish it from 447nm, since 473nm falls within the traditional definition of blue while 447nm usually doesn't. However, really true blue is closer to 460nm or 465nm so that 473nm is already trending in the direction of cyan (which is halfway between blue and green). 473nm is closer to blue than to cyan. Because this wavelength is more expensive, people on a budget usually get the cheaper wavelengths first and gradually work up to this one.
And finally, the apparent color of a laser beam or dot can vary quite a bit with brightness because of the Bezold-Brücke shift and Abney effect.
handprint : adaptation, anchoring & contrast
Abney effect - Wikipedia, the free encyclopedia