How Does Dust Affect A Burn

vbimport

#1

Hey,

After burning a disc today I noticed that there was a piece of dust sitting on the disc, after removing the dust you could see a part of the disc that had not been burned, I am just wondering how the drive handles things like this, does it think it has burned the data when it hasn’t or does it make some kind of compensation?

Funnily enough the disc in question achieved the best scan I have ever seen, even from most DVD-ROM’s!

The scan is attached.


#2

first of all you should set kprobe to scale automatically not fixed.
second it will depend but in my experience that disc is a coaster. might want to try a transfer rate test and see if it gets stuck during the read


#3

Thanks, I will try that that test.


#4

Ok, I done the Transfer Rate Test and from what I can tell it came out pretty good, there is no affect on the readability of the disc, I guess the last test is to actually watch the movie and see how it goes.



#5

If dust particles are large enough, and numerous, things can get pretty awful.

With discs in spindles, this has actually given me trouble more often than I would like to! :doh:

Actually I think it’s possible that many users are not aware of this problem, so I’ll post an “extreme” example just to get people scared enough so they will pay attention… :stuck_out_tongue: nyark nyark… LOL

TYG02 (Verbatim DatalifePlus 25-discs spindles from 2005/09)
Both burns with NEC3540A 1.W5

1. First disc of the spindle: lots of dust (straight from the spindle, no check before burning)
Lots of dark spots are visible after the burn, just under each speck of dust.

2. Second disc of the spindle, clean (wiped with antistatic before burning)
Visually perfect surface after the burn.

As I stated before, this is probably the most extreme example of this dust issue. But who knows? :bigsmile:




#6

I allways reburn disc’s with to manny dust speckles.


#7

So do I, but now I have an antistatic cloth so it’s not an issue for me anymore, unless of course I stupidely forget to use it (which still happens from time to time ;))


#8

You can have a look at my experience with dust on a DVD in this earlier thread:

What a single speck of dust does to scans

Note: This is the effect of dust during reading, not during burning. The result is similar though, except that any problems with dust during burning is permanent on that disc.


#9

@ Francksoy:

Where do you get your antistatic cloths? Even if you’re wiping radially, you’re not worried about scratching the burn surface? Thanx.


#10

Yeah, I remembered this one :slight_smile: - thanks for the head up.

@ninbang: I bought it from a local shop. No problem with scratches, first because I don’t need to press the cloth onto the surface, secondly because in my experience, light radial scratches seem to have no influence whatsoever on the burning quality. Before the antistatic cloth I used to wipe the discs with average cotton wool and cleaning fluid (isopropylic alcohol), this left many tiny radial scratches and I never noticed a degradation with my burns. Still, the antistatic cloth if a far easier, faster and safer method. :slight_smile: - of course, won’t wipe out the possible fingerprints :wink:


#11

Hmm … I’ll have to look into that. Sounds like a more economical alternative to using compressed air. Thanx for the info. :slight_smile:


#12

That’s for sure!! :iagree: - still, compressed air is handy for the drive itself… :wink:


#13

Edit (I’m totally mad :stuck_out_tongue: ) - just tried with an el-cheapo antistatic feather duster (ugly looking fluo synthetic stuff made in China), well it does the job just as well! :bigsmile:


#14

I use a can of compressed air. Cheap (in bulk packs) and doesn’t touch the disc surface. I never used to check my discs for dust, and going back I’ve noticed a lot of dark specks on the disc. Never affected performance and all are still readable with near-perfect transfer curves. I might end up reburning though (perfectionist in me).

-Evan-


#15

I find dust particles, and dye imperfections, don’t ussually add a lot to the PIE error rate, but rather add PIF error spikes to the disk. This is because the dust does a lot of damage to a small area. So the PIE error rate isn’t hugely affected as it only affects a few frames, but the PIF error rate is affected greatly because the damage on the frames it does affect is heavy.


#16

Exactly my experience :iagree: - though when the dust is very fine and evenly spread (I still wonder why this happens, actually :confused: ), it seems to also affect PIE, but in lesser proportions.


#17

I use a microfiber made for glass or a lingette if there is a lot fingerprint on it