2 Qestions...

[Ace82]

MORE THEN 1 OPTION.
But please, select only one of each one:



True or False??::   "blu-ray", or 405nm laser diodes produce much more "emissions of radiation", then our eyes detect by form of light?  Meaning, that there are photons outside of the average human's eye sight color spectrum, and that only a percent is observed and interrupted into the human mind as a "violet dot" OR WHAT EVER YOU CALL IT.




Personal observation:

I love  analogies...  

Words by Ace82:
(regarding laser light...)
"The longer the wavelength, is to the duller the knife.  So for the same(as to shorter wavelength) amount of "cut", takes more energy, or more time, but is more broad, or ruff, of an impact.  

To where as, the shorter the wavelength, the sharper the knife.  So for the same (as to longer wavelength) amount of "cut" takes less energy, and less time, but is much more narrow, or finer, of an impact.

 

[LRMNmeyer]

I thought it was a good analogy, and I voted so. I didn't vote whether it was true or false though, as I don't know enough about the subject to have a definite answer.

 

[treb76]

There are photons being released that may be in or out of the human's perceivable range, but they should all retain the same average wavelength (not accounting for wavelength changes as the diode warms).
Bluray spec, I believe, calls for 405nm +- 5nm.

Basically, you should be seeing the entire power.

My $0.02

 

[Joe]

There are photons being released that may be in or out of the human's perceivable range, but they should all retain the same average wavelength (not accounting for wavelength changes as the diode warms).
Bluray spec, I believe, calls for 405nm +- 5nm.

Basically, you should be seeing the entire power.

My $0.02

Thats what I was thinking. Even -5nm shouldn't affect our ability so see it that much at the level of intensity that a 100mw laser provides. Even X-rays have been reported as visible by Roentgen and others given a high level of intensity.

 

[Ace82]

What about fluorescing? I mean, take a tennis ball, and put it in a dark room. Then point your blu-ray laser at the white wall, and see how much it lights up the room. Then point the laser at the ball and see how much it lights up the room…. Ok. Like IR, you can’t see the full power, although in near IR the average human’s eye can detect light, although not enough to see the full power. Green lasers can look “more powerful” then they really are, because our eye’s detect green the most. And blu-ray, I BELIEVE that a fraction of the intensity can be observed by the naked eye, depending on what surfaces it reflects off of, but that the average human eye doesn’t perceive it as bright as it “really is”, like between red and inferred would be.

 

[treb76]

I could see that happening as the wavelength decreases from say 473nm (blue) to the ultraviolet (<405nm), it would be dimmer and dimmer. But technically, you are seeing full power, it's just your eyes just don't perceive it as bright. Take, for example, a digital camera. If you change the exposure (or is it aperature?) settings from say f2.8 to f8, the sensitivity of the picture is decreased. You are still seeing full power, just perceived in a different way.
It's all about perception.

 

[RA_pierce]

I could see that happening as the wavelength decreases from say 473nm (blue) to the ultraviolet (<405nm), it would be dimmer and dimmer. But technically, you are seeing full power, it's just your eyes just don't perceive it as bright. Take, for example, a digital camera. If you change the exposure (or is it aperature?) settings from say f2.8 to f8, the sensitivity of the picture is decreased. You are still seeing full power, just perceived in a different way.
It's all about perception.

F stops are for aperture.

Isn't some of the shorter wavelength light absorbed by they eyeball too?
I remember reading somewhere about how old dudes have trouble viewing ultraviolet light because your corneas will turn yellowish (which absorbs violet light) as you age.

Assuming this is true, then your cornea also contributes to the perception of violet/ultraviolet wavelengths as dim. But it's really the same concept as with IR. The eye is less sensitive to some wavelengths.

Joe: visible X-rays? Neat. What would they look like? :-? Could it just be fluorescence?

 

[691175002]

I would have to disagree on both counts.  By definition a laser is monochromatic;  they are all exactly the same (even down to phase shift).  As has been said, its not that you are only seeing X% of it, just that the human eye considers that color less bright

As for the knife analogy, while shorter wavelengths could be considered more "accurate" in the sense that they can be focused more precisely, that has almost no bearing on your analogy and is more a matter of optics than the light itself.  Low wavelengths are not inherently more accurate at the scales we are talking about.  (But they will be more precise in applications like microscopes but that is a different topic.)

The far more crucial aspect in terms of cutting ability is the amount of the light that is absorbed.  For the majority of materials, 405nm will be absorbed more than red; however, IR is essentially pure heat in practice and will burn far better than both.

What about fluorescing? I mean, take a tennis ball, and put it in a dark room. Then point your blu-ray laser at the white wall, and see how much it lights up the room. Then point the laser at the ball and see how much it lights up the room…. Ok. Like IR, you can’t see the full power, although in near IR the average human’s eye can detect light, although not enough to see the full power. Green lasers can look “more powerful” then they really are, because our eye’s detect green the most. And blu-ray, I BELIEVE that a fraction of the intensity can be observed by the naked eye, depending on what surfaces it reflects off of, but that the average human eye doesn’t perceive it as bright as it “really is”, like between red and inferred would be.

You are absolutely seeing the full power. Every one of the photons that enter your eye are treated exactly the same as any other wavelength. It just so happens that the cones and rods in our eyes aren't as stimulated by that particular wavelength and the brain tones it down.

I see what you are trying to say, but your terminology implies that a certain percent of the photons are ignored, and this is untrue.
You seem to consider power and brightness the same, however they are very different.

You are seeing the full power of the blu-ray laser. It is just that the power does not translate as well to brightness as green does.

 

[Ace82]

I could see that happening as the wavelength decreases from say 473nm (blue) to the ultraviolet (<405nm), it would be dimmer and dimmer. But technically, you are seeing full power, it's just your eyes just don't perceive it as bright. Take, for example, a digital camera. If you change the exposure (or is it aperature?) settings from say f2.8 to f8, the sensitivity of the picture is decreased. You are still seeing full power, just perceived in a different way.
[highlight]It's all about perception.[/highlight]

Everything is about perception, HOW DO YOU SEE IT? Even the word, "SEE", is conditional, some people might combine a certain percent of what they "feel", with what they "see"... Hence the phrase, "love is blind", meaning that the feeling alters your perception.

As so has my 2 questions been perceived differently (judging from the mixed responses), depending on what my questions are asking you as a individual.

So, "its" not (referring now to 691175002's post) that you are only seeing a percent of it, "it's" that the human eye considers that color less bright. Well, what is "it"? I'll tell you. "It", is 691175002's perception of what my question is, to have him give his answer to "it".

So because of everybody’s different perceptions, a clear answer is practically impossible, because it's the question that is perceived differently through different eyes.

And 691175002's, could you tell me that you could accurately cut a shape out of a piece of paper with a butter knife the same as a razor blade?

"Ignoring a certain amount of photons", (I like that) being untrue...humm. What about your automatic dilation of your eyes, that involuntary react to light, even they ignore the photons of inferred. And you don't see the full power. You can't even see it burning your retina. I guess, since you can't see the light, then it must just be "pure heat". ;D

Open your mind. More then meets the eye. There is always something going on, ever so slight, but not everybody can see it.