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04-26-03
I have compared (same titles) two cds. one treated exactly ... Warrenh
04-26-03
I don't see anything wrong with your lengthy process if it m ... Albertporter
04-26-03
The small blue rings from compact dynamics, makers of optrix ... Geoffkait
04-26-03
Buscis2; well stated case, and i agree w/ the above posts t ... Garfish
04-26-03: Herman
I may be able to shed a little "light " on this.
"I still, to this day, have not been able to figure out why Green is the color of choice although, I have been told that it is simply the values of each of these colors (Red laser light and Green) that work together in unison to "neutralize" the light."
The correct term is absorb, not neutralize. A green marker is green because it reflects green and absorbs other colors such as red. Since red and green are opposites on the color wheel, green is especially good at absorbing the red. Black should also work because it absorbs all colors. If you used a red marker it would reflect red, exactly the opposite of what you want.
Herman (System | Reviews | Threads | Answers | This Thread)
04-26-03
Buscis- i tried the cd lathe from a local dealer (he treated ... Sutts
04-26-03
To hell with the naysayers albert. to hell with them i say! ... Buscis2
04-26-03
Herman, hi - the typical cd player laser light is infra-red, ... Geoffkait
04-26-03
Thank you herman. in terms of terminology, you are right, i ... Buscis2
04-26-03
Sutts, that sounds highly unusual, considering the first tra ... Buscis2
04-26-03
I love to tweak but cannot perform the cd edge bevel because ... Megasam
04-26-03
Megasm, sometimes, even golden rules need to be broken. fort ... Buscis2
04-26-03: Herman
HI Buscis, I don't disagree with the results you claim as I have no first hand knowledge, but again it is a matter of terminology. If you shine a pure blue light onto a yellow surface the surface will appear to be black because it does not reflect any of the blue light. There is no cancellation, the blue light is simply not reflected so there is nothing to see.
To Geoff, yes it is infrared but 790 nm is barely outside the visible spectrum so it too will be absorbed by most green surfaces. As to being downshifted, in most cases, a laser entering a material will exit that material at the same wavelength. If it slows down as it enters the medium, it speeds up as it exits. There are a few materials that re-radiate laser energy at harmonics of the incident beam such as KTP crystals that convert a 1064 nm Nd yag laser to 532 nm, but light entering a compact disc comes out the other side at the same wavelength.
I offer this not in the spirit of disagreement, but in the spirit of attempting to clarify.
Herman (System | Reviews | Threads | Answers | This Thread)
04-26-03
Ahhh, i love you guys like brothers and this some great stuf ... Buscis2
04-27-03
First of all, speaking from a purely technical point of view ... Sean
04-27-03
Sean, go off the thread, i will email you my address, send m ... Buscis2
04-27-03
There was a good shootout in audio musings #14, 2001. they h ... Metralla
04-27-03
Herman, hi again, the reflected laser light doesn't have a c ... Geoffkait
04-27-03
Another wrinkle in the cd edge coloring problem. here is li ... Geoffkait
04-27-03
Hey ed, i'm trying like mad to email you, but i get an " ... Warrenh
04-27-03
Geoffkait writes: "until light in the plastic hits the ... Metralla
04-27-03
Metralla, you're very close; the index of refraction of poly ... Geoffkait
04-27-03
I use optrix by compact dynamics and the micro smooth from m ... Jsawhitlock
04-27-03
Hi jsawhitlock, are you washing the cd and thoroughly drying ... Buscis2
04-27-03
What do you use to dry cd after washing? thnks. Peterx
04-27-03
Hi peterx, i use paper towels, but, i do not rub! i simply p ... Buscis2
04-27-03
Buscis2, i use cotten lint free wipes for computors and dry ... Jsawhitlock
04-27-03: Herman
Sorry to hijack this thread with a discussion of physics, but I have done a little research into the subject of light absorption and have found the following.
Light will be absorbed by a system when the frequency of the light is in resonance with some natural frequency of that system. When light is refracted, it's speed changes and so does the wavelength, but the frequency does not. Therefore the absorption of a material is independent of the wavelength.
Herman (System | Reviews | Threads | Answers | This Thread)
04-27-03
Buscis2: i posted earlier findings about the experiments th ... Sean
04-27-03: Herman
Sean, I am not a laser engineer so I can't give definitive answers but I do have a bit of laser experience as I make my living repairing medical lasers. I do have few thoughts on the subject.
Some energy is reflected and some not. That is the way the whole scheme works. Areas that reflect enough light are interpreted as one digital state and those that don't are interpreted as the other state.
When I point my red laser pointer at a disc I see that it scatters the light. Depending on the coating or lack of coating on the top of the disc some discs transmit a portion of the light. I can see it through the disc. Those that have a heavier coating of paint seem to block it. I have no way of knowing if they absorb it or reflect it. The pointer is a shorter wavelength than the laser in the CD player (around 650 nm vs 790 nm) but they are close enough to reasonably assume that they would act in a similar fashion. It is possible to coat a surface with materials that will act upon a narrower range of wavelengths than this so it is possible that my assumptions are wrong.
The big question is whether this scattered/reflected light will be picked up by the sensor in the player and cause errors. It seems like it would be very simple to set up test equipment to capture the bit stream from a digital output and see if it changes with various disc treatments. I don't have this type of equipment so I can't do it but it can't be all that difficult for someone who does. It would be interesting to see what the results of such tests were.
Herman (System | Reviews | Threads | Answers | This Thread)
04-27-03
Good info herman and thanks for sharing. i wonder if these ... Sean
04-27-03
Strictly guessing, wouldn't some light polarization on the c ... Viggen
04-27-03: Herman
It might be better to ask an ophthalmologist.
Herman (System | Reviews | Threads | Answers | This Thread)
04-27-03
Herman, viggen was right. we want optimum performance, so a ... Sean
04-27-03
If it doesn't cost a lot, i'm willing to keep an open mind. ... Elmuncy
04-27-03
Hey sean, you are very very close. i am more or less reinfo ... Viggen
04-27-03
Hi elmuncy, in response to your question, i don't know if yo ... Buscis2
04-28-03
Strangely enough, on mercury living presence cds red marker ... Geoffkait
04-28-03
Geoff: how can you tell if one marker color sounds better o ... Sean
04-28-03
Sean - the so-called permanent markers (ink, not paint) can ... Geoffkait
04-28-03
Hi jsawhitlock, i cannot concur with your experience of hazi ... Buscis2
04-29-03
Geoff: thanks for the info. i'll have some of these marker ... Sean
04-29-03
Sean- re: the cd lathe, as i indicated earlier, i had a loca ... Sutts
04-29-03
Now you guys have me thinking about purchasing a cd lathe! a ... Mprime
04-29-03
Hi mprime, if you are considering the purchase of an audiode ... Buscis2
04-30-03
To expound upon what buscis2 stated about the audio desk sys ... Sean
04-30-03
Sean,i am looking forward to your findings. i also stopped a ... Buscis2
04-30-03
Dvd player lasers are 655 nm (red) while almost all cd playe ... Geoffkait
04-30-03
Thank you for the clarification geoff. and your response bri ... Buscis2
04-30-03
I have found 2 disks of the same recording never sound exact ... Mejames
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