PIF Spikes from Pio 111D on BQ 1655 with Verb 16x

(Since the problem involves two units and at least one disc brand, I placed it here; it could also go to the Benq or Pioneer forums depending on which unit is considered responsible)

The situation is like this: when I scan DVD discs on a Benq 1655 (BCDB original fw) unit I sometimes get high PIF spikes (see pictures). This happens on maybe 50 % of the burns, the others are excelent (these would be too, were it not for the spikes). The discs are written on a Pioneer 111D unit (1.23 original fw), at 4x - 8x speed. The discs in question are Verbatim 16x +R made by CMC. With other brands I haven’t noticed these results, however this has been my brand of choice for some time.

I scan at 8x with Nero CDSpeed 4.60. I also tried scanning at 8X P-CAV and the spikes disappear. On these discs and this unit, the spikes are usually consistent: they show up identically in all consecutive scans of the same disc (there have been rare situations, one or two, when the spike dind’t turn up in a second scan). They have turned up in almost any place on the disk; there is always just one large spike (or none at all). However the read test is always fine (absolutely no drop in read speed near the spike location, or anywhere for that matter - see pictures).

The discs are written by the 111D in Windows XP on an AMD Athlon XP 1800+ with 512 MB RAM and a VIA KT400 Gigabyte MB, the power supply is of good quality and has twice the power needed, the writer (111D) is connected as the secondary master (along with a hdd); I burn with Nero 6.6 and there are no other major applications running during the process, no FW or AV. As far as I can tell, there are no differences in the burning process between the discs with spikes and those without (same hardware, software, no other applications running, no changes in the environment). The scanner (1655) is set as master alone on it’s IDE channel (the two drives are evidently part of different systems).

I am tempted to belive the discs are fine and the scanner (1655) gives false indications. It has shown similar spikes with discs written on an LG 4163 (and fine read tests), also on maybe 50% of the burns (the famous incompatibility); on the discs written by the Benq itself, there were horrible spikes on TYG02 (which I thing were real) and inconclusive (yet generally mediocre) results with Verbatim 16x. However I don’t have any other unit to scan on at the moment, so perhaps you can share your opinions.

And the pictures:

Disc 1: Verbatim 16x +R (CMC) written at 4x
The PIF spike has about 900 of the total sum

The read test for Disc 1:

Disc 2: Verbatim 16x +R (CMC) written at 6x
A second case of ‘disc with spike’. The spike near the end has about 500 of the total

The read test for Disc 2:

Disc 3: Verbatim 16x +R (CMC) written at 4x
This is an example of a ‘good burn’, which is more or less, a burn like the first ones only without the PIF spike

I am first interested in the true quality of the 111D burns; then in the scanning ability of the 1655.
Thanks four your qualified and ontopic opinions.

Those spikes would not be bad enough to cause reading slowdowns in all likelyhood so seeing a perfect TRT is no reason to believe that those errors don’t actually exist. Usually spikes like this are caused by specks of dust at the time of the burn or the scan, small dye defects, small scratches, etc. While they don’t make for a ‘pretty’ scan, they’re not a major concern. I see similar random spikes with most of my media from time to time, media that will burn with very low error levels except for the occasional spike - it’s generally from dust or small ‘knicks’ in the discs or dye defects. You can take a bright flashlight and closely look at the discs for any of these potential problems, you might be suprised what you see that isn’t immediately obvious under normal inspection of the disc. I have had a number of discs that would possibly scan with zero PIFs or single digits PIFs if not for the amount of dust on them before and/or after the burn.

The PIF clusters in your scans are typical of what you’d get with a speck of dust on the disc surface. If the speck of dust is present during the burn, the PIF cluster will be there in all subsequent scans. If the speck of dust is only there during a scan, the PIF cluster will be gone as soon as the speck of dust is gone.

There are other possible explanations, but this is by far the most common one.

This explanation is somewhat unlikely as most of the discs with this problem were bought in wrapped cases and unwrapped just before burning. I also closely inspect every disc before burning and blow or otherwise remove (without scratching) any particle I see on the surface under a bright light (distant enough not to affect the dye).
The spikes aren’t related to batches, the proportion in most batches between good burns and those affected is about the same as the overall ratio.
If you belive extremely small particles could lead to these errors than most of the discs we burn should have them, to some degree.

And to some degree basically all of my burns ARE effected by small dust specks, just to a lesser degree. As I said in my previous post, I have a number of scans that would probably have single digit PIFs if not for the amount of small specks of dust on them. I have discs that even have small circles (about 5mm diameter) throughout the entire surface (require a bright LED light to even see)and they get 200-400 PIFs. Without those circles they would likely burn with extremely low PIFs. And unfortunately much of the media I use has a fair amount of ‘dust’ specks on them even from a sealed spindle.

Which is exactly what happens. :iagree: - Most DVDFreaks use canned air to blow particles out of the blanks. Personnally I use a duster because I found a very good one.

Many blanks come dusty right out of the spindle (and Verbatim can sometimes be really annoying with this, at least in Europe) and you can see PIF clusters like these in most scans of non-dusted media.

BTW many speckles of dust on a blank or a burnt disc can only be seen under a halogen light at a certain angle. Forget daylight and/or incandescent light.

Anyway as [B]scoobiedoobie[/B] mentions, such clusters/spikes as the ones you show are really nothing to worry about, they’re minor (understand: neglectable). :cool:

I think it’s nothing to worry about. TRT is fine. Random spikes mean nothing if they are that small and the TRT is fine. :slight_smile:

If it were dust then the whole batch of discs should have it; remember, I only buy discs in wrapped cases. I also use various devices :slight_smile: to blow any particles away from the surface of the discs.
These spikes also seem rather ‘wide’, that is distributed on a relatively large surface of the disc (they are not concentrated on one block or whatever it is called). One tiny particle of dust could not generate such errors, unless the scanner would do something wrong too.
So I still think there is something wrong with the scanning process - it might be extraordinarily susceptible to some type or pattern of errors and when it encounters them, it starts giving false positives. Or if the indications are real, then it could be because of (random ?) defects in the media or even something wrong with the writer.
Regarding the degree of concern, one spike of 100 - 200 PIF might be acceptable, but spikes of 1000, sometimes more can not be considered anymore as part of a “good burn”. High PIF levels have been correlated to faster media aging and I can’t be sure of how these regions will evolve. Keep in mind this is practically my best media at the moment, also used for backups. So I welcome any other opinions and I will keep you posted if I find a cause, or a solution :slight_smile:

That’s a wrong conclusion. The surface of a DVD can attract dust particles which are floating in the air. I’ve even had discs where I removed dust with compressed air, and in the 1-2 seconds it took to move the DVD to the drive tray, another dust particle managed to attach itself to the disc surface.

So your discs don’t have to come with dust already attached - it can happen after you take the disc out of a cakebox or jewel-case!

That’s a whole lot of dust to attach itself in a few seconds while the disc is out of the box. By the way, I always keep the disc ‘face down’ and when I inspect it, it is held at 90 degrees or less to the horizontal :smiley:

Static electricity can be your enemy too. Using an air duster may cause a slight build up of static electricity.

If you discs are dusty from the spindle, you are probably better off using an air duster to get rid of the particles. My TY spindle is very dusty and I have already burned several DVDs with large dust particles leaving a shadow on the dye. I had to toss them out because the drive slows down while reading those areas.

The worse incident I had was with some DVD+R form TDK. Several of their discs had crusty residue left on the surface. Compressed air did not work and I had to rub the stuff off with my finger nail. Those discs went straight to the can.

Which media code did those TDKs have?

No its not! :disagree: I’ve seen (on a daily basis) such PIF cluster/spike as the one showing in your scans get caused by extremely tiny particles, hardly detectable visually. I think you greatly underestimate the amount of dust particles in suspension in any room,and greatly overestimate the “spikes” in your scans. They’re totally neglectable and don’t represent anything special. We see these everyday.

As I mention in my post above, most CDFreaks use a duster or canned air to avoid these small PIF cluster/spikes (though they are not a problem) to produce the oh-so-clean scans you can see in various threads. Scans of non-dusted discs often look just like yours. Not everytime, but often, let’s say two times out of three (roughly).

Now you’re of course entitled to reject the most sensible and simple explanation (dust particles) and look for a complicated one, have it your way. :bigsmile:

This is a strange logic.

I think it may also be possible that some ‘dust’ particles are more opaque than others, as I have some ‘dust’ specks that create a much more significant PIF spike than others despite looking visibly similar in size. In those cases, it may be more accurate to describe those specks as residue from the discs themselves or similar, maybe bits of disc that have made their way onto the hubs, edges, and dye surfaces themselves at the time of packaging. Sometimes I’ll see a random tiny speck that looks metallic as they shine when I use a bright LED light on them, and certainly that’s not your typical ‘dust’. I have a spindle of Memorex RICOHJPN R03 that burns very well with a few random spikes of very similar characteristics to those above that drive the PIF totals to 1-2k+.

Having said all that, we still may not be dealing with dust at all, it could be below the surface on the dye/in the dye. With those Memorex discs I mentioned, although there is some very small dust particles often on them, I’m not convinced that it’s actually the dust to blame for the larger spikes. I think it may be something below the surface at the time of manufacturing the discs, maybe from a less than optimal environment (these are made by Ritek after all…). Under a bright LED light you might be suprised at what you can spot at different angles, for example a significant amount of my media has assorted ‘speckles’ (tiny air bubbles possibly) below the surface, probably in the plastic layer. Depending on how bad they are, they may only have a minor impact on scans such as a bit higher density of PIE levels, or it may be the cause of some PIF spikes and quite frankly I’ll probably never know for certain. It’s very difficult to photograph but I’ll probably try taking photos of them if I ever get a digital SLR.

Here are two threads that discuss the effect of dust specks on Disc Quality scans:

How a tiny bit of dust can ruin your scan

What a single speck of dust does to scans

Drage, you forgot this one:
How Does Dust Affect A Burn

Beter than none at all :slight_smile:

When ‘dust’ was mentioned I presumed you are talking about the sticky type found on larger areas of the disc, the sort present in poorly handled or stored discs before packaging. I explained why I don’t belive this can be the effect of dust attached in the few seconds the discs are out of the case, before writing: there is too little time, I closely inspect every disc (up until the time I place it in the tray) and the spikes are too wide (the errors too loosely distributed) for them to be produced by just one small (and thus practically invisible) particle.
Besides, I haven’t generally found this exact pattern (one large spike) on other types of discs, namely YUDEN000 T02, written / scanned by the same units. And the Yudens are said to attract much more dust :wink:

PS: I will try to inspect the discs under all sorts of lights and beams, to find out what I’m missing :slight_smile:

The dust might be on the tray or inside the drive as well.

I have taken (again) a close look at your scans and these spikes are on the contrary quite localised, the errors are not “loosely” ditributed at all. I strongly suggest you take a look at the threads linked to above thanks to [B]DrageMester[/B] and [B]dodecahedron[/B] before keeping the discussion going, as these thread contain empirical evidence, with scans, that such spikes can be caused by tiny particles. Also, as you didn’t say anthing about it, I quote myself:

BTW many speckles of dust on a blank or a burnt disc can only be seen under a halogen light at a certain angle. Forget daylight and/or incandescent light
Are you sure you inspect your discs for such particles in the right conditions…? It NOT easy to detect them. :disagree:

Funny you would mention that, I’ve been following the same train of thoughts recently. :slight_smile:

Their shape, also, could be a variable (rather round, rather flat etc…)

I also came to wonder if the polycarbonate optical properties could make a difference on the impact of small particles on the surface: after all, the impact is not only due to laser occlusion, but also laser diffraction, so chaotic behaviour is at work and many variables can be present we don’t even think of.