Common issue with media burns

vbimport

#1

what causes this? i see it alot with various writers (not so much with nec) the burn looks excellent then at the end goes to hell…is this a common thing with subpar burners that dont have correct write strategies?

this is the end of a litey 812s burned at 4x CMC F01 media sold as HP DVD+R 4x (really overpriced imho).


#2

It’s because the highest burn speed is reached at the end of the disc.


#3

no im watching the burn speed actual time…its a constant 4x CLV.

Its the USOJ firmware heres the same batch burned with USOG :wink:



#4

I think it can be down to one of two things.

First is balancing. A slightly badly balanced disc will be harder to keep correctly calibrated the wider the laser goes out. Plus, contrary to what you might think intuitively, because the spin speed is slower on the outside the disc is more likely to wobble slightly in the drive at the outer edge. This also explains why some drives suffer this more than others; some drives can dampen these effects down more.

Second is the way the dye layer is “spun” during manufacture. On some discs there is an uneven spread across the disc; some discs will be no good at the start of the burn, others (more commonly) at the end.


#5

or of course it could be a bad write strategy for a disk as shown above…identical batch two firmwares.


#6

Yes of course :slight_smile:

Although I’ve always suspected that in the case of errors “running away” in the last 10-15% of the disc, the bad strategy is only a contributing factor and there is usually an element of media error in it as well.

Example: “proper” Prodisc S03 vs “Bulkpaq” B-grade version of same. On a Pio 106/7 or NEC2500A, both discs are perfect and perform similarly. On the 105 or LiteOn 851s on the other hand the more expensive S03s also perform perfectly, but the B-grade discs have problems right at the end.

Not 100% sure why, but I think perhaps newer drives/firmware are just more capable of dealing with discs with manufacturing faults at the end successfully, more than just write strategy on its own, in the Prodisc example the write strategy is and should be the same for the good and slightly bad media.


#7

Jase; I have a 50 disc spindle of ProdiscS03, which I purchased as ProdiscS03 from ACCA Recording Products. Would this be Grade A or Grade B? Is there something in the medai code thst will reveal this?
My NEC 2500A with HV2b4 burns these better than TYG01 (PI avg 3.3, PO avg 0.02). My Lite-On 812S with USOJ Burnfix & Spdadj creates barely readable standalone discs on the same media.
What am I missing here?
Thanks for your response.


#8

the NEC has the correct media stategy for those disks your 812 doesnt…i went back to USOG on my 812 and am getting better burns for some media.


#9

No direct way of telling what grade discs are by looking at them unfortunately.

Bulkpaq always have sold grade B or below media. They are a budget brand. That’s the only way I know.