Different Dyes - Why CD's and not on DVDs?

[bindairdundat]

This is some information that I have found on CD's and noticed that most DVD's use AZO or a Metal AZO dye.. if they are the "worst" then why are not DVDs using phthalocyanine as their dye and can one find a DVD with gold reflective layer instead of silver? Not many by my count. I have home videos that I want to stick around longer than 2 years as I have to recycle the original tapes.

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"The best dye is phthalocyanine, with cyanine in second place and metal azo as the worst. "
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This quote was in reference to longevity of the disk.

[lenti_75]

you'll se different dyes. just a matter of time...like cd's

[BobK]

> I have home videos that I want to stick around longer than 2 years as I have to recycle the original tapes.

They still sell tapes pretty cheap. Why not just buy a few if you want to keep the home videos?

[lordsmurf]

AZO (Prodisc, MCC) is better than cyanine (and derivatives) crap (like Princo) .. at least as it exists in discs right now.

AZO is a proprietary chemical of Mitsubishi (as far as I know)

Even then, dye is only a portion of the battle.

Early DVD-R had gold reflective (RITEKG01 for example), but it was more expensive and honestly did not work as well as latter media. I think DVD-RAM may still use gold.

With DVD, forget what you knew about CD. Difference situation entirely. No comparison.

[vcdforme]

Lordsmurf,
what is so different "entirely" about the CD dye vs DVD dye?
Aren't both formats are still using red laser spectrum?
It's the software that determines the readability between the
two formats. The dyes should be quite similar.

Also,
Where do read that AZO is good, or better than Cyanine?


Isn't AZO proprietary of Verbatim?

I'm very concerned about this.
From what I've read, if our discs are in fact made of AZO,
we are seriously screwd. Unless, Verbatim has found a way
to fix their longevity problem.

[QuaiBoy]

Verbatim is owned by Mitsubishi Chemical. Says so right on the cakebox label, CD or DVD-R.

-Evan-

[lordsmurf]

I have no idea what you're talking about, in terms of a "problem" with lifetime. Verbatim is as hailed as Taiyo Yuden in the CD-R arena.

But even then, the dyes are different. They may share some chemical components, and the round shape of the plastic, but not much more. Seriously, apples and oranges.

[solarfox]

what is so different "entirely" about the CD dye vs DVD dye?
Aren't both formats are still using red laser spectrum?

Actually, no, they're not. CD's use an infrared laser at 780nm. This is why those "black" CD-R's are able to work -- the "black" material is opaque to the visible-light spectrum, but transparent to infrared wavelengths. (It's the same plastic material they put on the fronts of TV/VCR remote-controls to disguise the LED emitters.)

It's also why those black CD's sometimes don't work in certain DVD players -- models which lack a dual-laser pickup and just try to read the CD using the visible-red laser can't "see" through the material.

[vcdforme]

Verbatim's metalized AZO may get you temporary storage, but Mitsui is proven to hold the data intact.
(we're talkin cdr here)
I've read of some tests where the AZO, under ultra violet light,
immediately started to lose its data.

CDr dyes have been quite heavily scrutinized and tested.
I don't really see any testing on DVDr,
only many opinions.
Where's the conlusive data?

[Capmaster]

Actually, no, they're not. CD's use an infrared laser at 780nm.

Actually, no. Cds use a red laser, not infrared. It includes components of the infrared spectrum, but the power vs. wavelength is centered in the visible spectrum. If it were an "infrared" laser you wouldn't be able to see it, much like a TV remote

[skebenin]

Ooh! I love misinformation.

Don't believe everything you read.

[vitualis]

The misinformation continues...

Sorry, but the reading laser on a CD drive is designed at 780 nm which makes it in the near-infrared spectrum.

http://en.wikipedia.org/wiki/Infrared

Regards.

[bindairdundat]

They still sell tapes pretty cheap. Why not just buy a few if you want to keep the home videos?

Tapes, including digital degrade rather quickly, I had some tapes starting to show degradation after 2 years. Unsheilded magnetic media is just not very reliable in the long term.

[bindairdundat]

I did find some information that phthalocyanine, the preferred CD dye, is actually invisible to the red laser, rendering it useless as a DVD recording media.

So, in retrospect, would it be better to use RW disks? Since the recording media is a rather exotic metal combination, and once it solidifies in the proper "phase", has this been known to change phase over a period of time?... IE (has the noncrystallized "pit" been known to turn into crystallized "land" over a period of time? Is this more immune to the effects of UV?.

[lordsmurf]

I did find some information that phthalocyanine, the preferred CD dye, is actually invisible to the red laser, rendering it useless as a DVD recording media.

So, in retrospect, would it be better to use RW disks? Since the recording media is a rather exotic metal combination, and once it solidifies in the proper "phase", has this been known to change phase over a period of time?... IE (has the noncrystallized "pit" been known to turn into crystallized "land" over a period of time? Is this more immune to the effects of UV?.

Phase change material is unstable, not suitable for long term.

[estariol]

The laser issue is far more complex than the laser wavelength, or the dye type, yes DVDr and CDr operate at different wavelegths (dvd has smaller pit sze and closer tracks). The glue used to attach the two disc layers has implications for dye material. So different dyes will appear there are just more variables to consdier with DVD's......not to mention the dual layer issues.