DVD Disc: A Dark Side

MichaelS wrote on 12/16/2004, 6:43 PM
I hit a problem today that I hope someone can shed some light on.

Usually, the eye can easily differeniate between the burned and unburned areas of a disc. After burning a few discs today, I noticed something abnormal about the way they "looked".

Several of my discs appeared to have a much darker band, what could be approximated at 30 minutes of materal, starting at the core (00:00:00) moving out. The disc then changes to a lighter shade (approximately 30 minutes of material) before reaching the unburned portion of the disc.

When I tested the disc, it failed where the first, darker band ended. What would cause the disc not to burn nearly evenly across the entire burned region.

The burner produced quite a few coasters before I caught the problem.

Any ideas?

Thanks

Comments

Mandk wrote on 12/16/2004, 6:47 PM
We had a similar problem with the weird shading the the coaster problem. Turned out to be a bad batch of media. Do you have a different brand of disks or at least disk from another batch you could try?
Cunhambebe wrote on 12/16/2004, 8:11 PM
Change the brand to Philips or Samsung DVD+R.
riredale wrote on 12/16/2004, 8:12 PM
A 4x burner burns at a constant 4x speed the whole way. A faster burner can't, though, because the rpm's would be too high for the inner tracks. So it starts out at a slower speed (maybe 6x) and after about 1/3 of the disk has been traversed, it switches to a higher burn factor, such as 8x or 12x. This is one reason why an 8x burner is not twice as fast as a 4x burner.

So what you're seeing on the burned side of the disk is the slightly different density of the laser burn due to the different burn rate. On a high-quality blank, the different burn rate should have absolutely no effect on playback, but I've seen some graphs that show "spikes" of errors on cheap media at the transition point.

Incidentally, last year when I had to burn 100 CD-R blanks quickly, I soon discovered that if I ran the CD burner at 48x for an hour or so, the laser would begin to fail and would burn in concentric circles on the disk. I assume heat was a factor because if I slowed the burn rate down to 40x the burner could go all day.
farss wrote on 12/16/2004, 8:19 PM
I think this highlights a need for DVDA to have a read after write pass. Yes, I've tried burning with a 3rd party app but much to our horror have hit compatibility issues as a result.
Perhaps the only way to sure the burn went reasonably OK is to try draging the files back onto the PC, if anything is seriously amiss the sector ECC should cause Windoz to chuck a wobbly.
Bob.

TheHappyFriar wrote on 12/16/2004, 11:06 PM
I've had nero pass the read after write tests but the disk STILL fails. That normally happens when the drive is starting to die though. So, I don't bother using those tests, I just test my disks in another computer/CD/DVD drive (i have a CD-RW & DVD+-RW in my comp).
Steve Mann wrote on 12/17/2004, 1:37 AM
The solution is simple - burn your DVD/- R at 4X or less. I burn mine at 2X and I've never made a coaster and no client has ever complained.

Steve
Jay Gladwell wrote on 12/17/2004, 6:24 AM
What DVD burner are you using?

What brand of media are you using?

What DVD software are you using?

Jay
Xander wrote on 12/17/2004, 7:14 AM
From my experience, I have found that burning DVDs has been less reliable than burning CDs. Anything valuable, I will burn duplicates. Currently using Sony discs at 4X, but they are no better than other brands I have tried. DVD-RW discs have proved the most reliable so far - maybe because they burn at slower speeds! Wonder how HD-DVD and Blu-ray media will stack up?
riredale wrote on 12/17/2004, 7:40 AM
Guys, I'm sorry you are having problems, but really, this whole DVD thing can be licked.

I've burned over 500 DVD-R disks to date, and never have problems. Many of these disks are burned right to the limits (4.36GB) and they have full labels on them to boot. No playability problems.

I attribute 75% of my success to using only Ritek G04 (and now G05) blanks. Heck, I've even burned the G04 blanks (4x) at 8x on my new Pioneer 107 burner, with no playability issues, though I do it only for my own personal use, not for disks that go to clients.

10% of the success goes to Nero Express, which has been utterly bulletproof for me, and the remaining 15% goes to the Pioneer drives. I used an A05 (4x) extensively, and as mentioned am now using the 107 (8x).

As I mentioned in the earlier post, the band you see on a disk burned at 8x or higher is simply the laser adjusting to the new rpm rate. It has no effect on playability.
briggs wrote on 12/17/2004, 10:52 AM
Like riredale, I also burn to Ritek G04 blanks using Nero Express (although using a Sony burner). Just finished a batch of 80 with no problems having spot tested on two computers and three standalone players.

-Les
Jay Gladwell wrote on 12/17/2004, 1:08 PM
Well, until Michael answers some basic questions, anything anyone says is merely speculation--shooting in the dark!

Jay
Steve Mann wrote on 12/17/2004, 4:30 PM
Pioneer A02, DVDA2, and the cheapest media I can buy. I've delivered about 200 discs in the past few months - not a single complaint. Not one coaster in the bunch.

Steve Mann
MichaelS wrote on 12/17/2004, 10:33 PM
Jay,

Sorry for the delay. I usually use Taio Youden brand disks with Sony burners and DVDA 1.

This particular problem is related to a batch of 8x Memorex Printables on a Dell laptop and DVDA 1. I've never experienced this problem on my large system. It's obvious now that the problem involves this new batch of discs and the burn speed. I dropped back to 4x and the problem cleared up.

I appreciate everyone's input.
scdragracing wrote on 12/17/2004, 11:08 PM
don't be too sure that you are in the clear.

i just had a month-old sony dru-700a flake out on me... for awhile it was creating discs that wouldn't play on some players, then it finally started that random banding trip, sorta similar to what was described earlier.

since i always use taiyo yuden or maxell, i knew that it wasn't the media, but until i saw the banding, it didn't connect with me that the laser was failing... my neighbor has a $600 sony desktop burner that had to go in to get the laser replaced, after very little use.

the pioneer replacement burner works great, no more sony's for me.