Which disc would you rather use?

vbimport

#1

Well, most of my CMC MAG E01 scan well @ 16x but this one was written by my old Pioneer 106D and showed a rather interesting 16x scan. Which disc would you prefer???

MCC01RG20 @ 4x Pioneer 111L

MCC01RG20 @ 4x Pioneer 111L 16x scan

CMC mag @ 4x Pioneer 106D - scans below


#2

I’d prefer the MCC01RG20 disc because I don’t like the 16x scan of the CMC MAG E01 disc.


#3

Aren’t the two CMC scans of the same disc?


#4

Same here, as expected. :wink: - no increase in errors in a 16X scan over a 4X scan gives the MCC disc a clear edge in my book, based on what I see here. Nevertheless…

…as I’m not familiar with the consistency of these Liteys @16X, and it’s only one testing drive, I’d say there’s still room for hesitation… :wink:


#5

Yes they are :wink: - one @4X scanning and the other @16X scanning. Same goes for the MCC disc. I believe that the difference for each disc between the @4X and the @16X scan is closely related to [B]cd pirate[/B]'s motivation to open this thread. :wink:


#6

:iagree: I’m basing my preference only on the available information - that’s all I can do. But drives behave weirdly sometimes, there are huge variation in quality of drives of the same model, there are sometimes significant changes in scanning behaviour between firmware releases (e.g. MYS2 to MYS3 for the Sony DW-G120A and somewhere between KL05 and KL0G for the LiteOn LH-20A1P), the power supply can influence the behaviour of a drive, a drive that heats up will usually produce worse scans, and so on…

So there’s always room for questioning the validity of scans when you haven’t thoroughly investigated the particular setup used, but I don’t think it’s necessary to include that disclaimer every time someone asks for an opinion, so I only do it when something seems fishy.

Since I assume that cd pirate is more interested in a general opinion of what other users prefer and not specifically interested in which of those two discs is better, I answered briefly and based only on the presented information. :slight_smile:

As I believe more in consistently acceptable scans in multiple drives at multiple speeds than I do in getting ultra-low PIE/PIF in a single scan, I would prefer the MCC01RG20 disc in the example above, because it shows acceptable results in all presented tests, while the CMC MAG E01 disc shows poor behaviour in one of the tests.


#7

@[B]DrageMester[/B]: my “nevertheless…” etc… was more directed to [B]cd pirate[/B] actually… :wink: => difficult to make one’s mind with @16X scans performed in drives which behaviour/consistency at high speeds has not throughly been exposed (you explained that better than me anyway :flower: )

My point is,[B] cd pirate[/B], that more data is needed to demonstrate that @16X scans are useful (which I do believe), as there are even more variables involved in @16X scans than in @4X/8X scans. I’m with you on this one (you already know that ;)) but to convice those who think that standard scanning speeds are sufficient to sort out media/burning quality, we’ll have to do better than that (just a couple of discs, a single testing drive and no additional testing like readability in standalones or TRTs)…

Don’t get me wrong, I’m not criticizing your input, just stressing the point.

I’d like to be more helpful, but my problem is that I stopped scanning at lower speeds (except from time to time) so producing significant comparisons between higher and lower speeds would ask of me to re-scan many discs and I don’t really have the time these days. Nevertheless, I’ll see if I can come up with something, I do have discs that have been tested at different speeds + TRTs + readability in picky players. Thing is, these were mainly discs with reading issues (which is the whole point actually…)


#8

I would prefer the CMC disc. The reason has to do with what I would consider as [I]real[/I] errors. Given that many of the errors have to do with the quality of the reader, and that different drives will produce different scans of errors on the same disc, I am looking for low errors and consistency at normal speeds. This is why I only scan with one drive and I do not compare any of my BenQ scans with my Liteon.

Just because a certain media is easier to read at 16X does not mean that the burn was of a better quality. It just means for that drive, that media was readable. For me, the lack of [I]decrease[/I] in the MCC disc when going from 16X to 4X, indicates that the errors reported at 4X are real. The converse holds for the CMC disc where the decrease indicates that the 16X errors are not real. As I am concerned with as close an approximation of real errors as I can get, considering that I have $30 test equipment, the CMC gets my nod as the preferred disc. I won’t buy CMC however.

Interesting observation. Thanks Pirate, I love to test my brain. :clap:


#9

I have scanned several discs in many drives. There’s one particularly interesting DVD that I have scanned in every drive I own except for my Optiarc AD-7170A. I just haven’t gotten around to presenting the information yet. For some discs in some drives high-speed scanning is definitely necessary to sort out the really good from the problematic discs.


#10

:confused: Sounds to me like circular reasoning (what on earth is a “real” PIE/PIF error?) associated with wishful thinking. I.e. it sounds like you have decided to believe so, and that you need flawed reasoning to support the belief…

If it ain’t so, would you please care to define what is a “real” low-level error as reported in a scan?


#11

No thanks.


#12

[B]chas0039:[/B]

An interesting alternative use/viewpoint for high speed scanning :slight_smile:
Would that apply to all discs which show a similar decrease at lower scanning speeds? as my own experiences would contradict this viewpoint.


#13

I thought you wouldn’t.

:slight_smile: OK here is a first example clearly showing that @16X scanning is able to catch disc issues that standard scanning speeds cannot.

Unless the validity of transfer rate tests is questioned, or unless someone thinks I’ve tampered with the test results, it’s evidence that trusting standard scanning speeds to sort out good/bad discs or burns is questionable at best.

More tests will be added.

Introducing 16X scanning as a possible better method to detect marginal burns or so-so media


#14

Is there something I said to piss you off? You seem intent on picking a fight.


#15

My basic assumption is that 1X scanning is the most accurate. I could be incorrect here but that is the way I learned it here and from other forums a long time ago and back then the stated reason for increasing the speed was to save time, not increase accuracy.

I also assume that scans reveal a combination of errors really on the disc and problems that the reader has while scanning. This explains why two different burners produce scans that are very different on the same disc. This is the conventional wisdom here and is the main reason experts say you should not compare scans from different burners.

I don’t have a proof for what is represented by scanning at 16X. My opinion is that we see increases in error reporting because of the difficulty most drives have reading accurately at high speed. This also makes sense.

The issue is this, as I see it. When we see more errors at higher speed, are we seeing actual errors on the disc or problems with the drive? Conversely, when we see no change at higher speeds, what is really happening? In the case [B]pirate[/B] presented, the real question for me is whether or not I can trust slow speed scanning because there, the CMC disc is better than the MCC.

Given that my first assumption is that slow speed scans are the most reliable, and that I am not sure, nor is anyone yet, what we are seeing at 16X, I am not really ready to abandon slow speed scanning. This is especially true when the case above does not make sense when the speed increases for the MCC disc and the errors don’t. Since 99% of the use for DVDs is at 1X I am more concerned with the way a disc will play at 1X. I am not presenting a proof, just an opinion. Thanks for asking.


#16

I think the purpose of home testing should be practical, not theoritical, i.e. sorting out discs and burns in better/lesser in actual real-world conditions (higher speeds, reading tests like TRT) rather than finding the theoritical truth about what errors are “really on a disc” (which is a rather impossible quest anyway, as PIE/PIF errors are [I]reading errors[/I] - how many times must it be repeated that scanning doesn’t really “analyse” a disc for its so-called errors?).

The whole higher-speed scanning thing started with t[B]he observation that discs showing good PIE/PIF scans at standard speeds could nevertheless have reading issues in standalone recorders, or troubled reading curves in a TRT[/B]. I’ve mentioned several times already, that nowadays it seems legit to expect a near-perfect reading behaviour from a DVDR in any reasonably good reader.

High-speed scans can catch a fair amount (sadly not all) of such problematic discs, this is my everyday experience (and I’m not alone on this one) thus they have a superior practical value, in my view, than “standard” scans, [B]whatever the theory says[/B]. Theory is theory, and [B]real-world often doesn’t agree with theory as we all know[/B]. If the theory about scanning was 100% sound, we wouldn’t even be having this conversation right now. :bigsmile:

IMO only those who never actually tried to find a consistent, undeniable correlation between figures in PIE/PIF scans at different speeds and real-world readability for a given disc, will stick to “standard”, “theoritical”, so-called “accurate” scanning. I don’t deny that according to ECMA standards, 1X scanning is more “correct”. But that’s entirely useless if this “correctness” cannot be linked to actual reading behaviour. Such instances (direct link between figures in a “standard” scan and actual readability) are difficult to find. It’s not like I never tried. [B]Instances of correlation between high-speed scans and actual readability, on the other hand, are far easier to find.[/B]

And I’m not trying to pick up a fight, [B]Chas[/B]. I was underlining, and tyring to make you realize, that your views on the subject rely more on faith, habit, and pure theory, than on real-world, empirical evidence (which is the only interesting thing IMO in home testing - the rest is academic and has very little practical value, except to compare burners preformance/quality).

In a way, I’m pickier than you are: the reading performance of a disc @1X or @4X is not enough to make me happy. :disagree: I’m expecting from a disc to be read flawlessly @max speed in most reasonably good readers. Thus I use, and advocate, testing methods that help in picking the media and burning methods achieving such performance.

See the link I posted above showing evidence of what I explained. Or don’t, but then I wouldn’t see the interest of discussing scanning methods, if dismissing evidence that doesn’t fit the theory is preferred to open-minded curiosity. I’ll post it again here for convenience : Introducing 16X scanning as a possible better method to detect marginal burns or so-so media


#17

If you really want to persuade people towards your theory, you would do much better being less hostile. I am very open to new findings and I have no bias whatsoever as to what is revealed by 16X scanning. I don’t know where you got the idea that I did. The only posts I can recall relating to scanning speed are on the 4X vs. 8X Liteon standards.

Your method of presenting your perspective came very close to shutting my mind to anything you might have to say. [I]Of course[/I], I am interested in finding out new information from scanning! Just consider being a little more persuasive rather than hurling insults to get my attention. You [I]really[/I] don’t know me if you accuse me of believing anything based on faith.

There, now let’s start over. I have no opinion whatsoever on 16X scanning. I’ll look at your paper and see what I think. Keep me informed.

:slight_smile:


#18

Wow so many replies!!! I’m happy for all the posts, I read every single one and I would like to say that yes, my post was not intended as a question of which disc I should actually use. Rather, to see what people thought about high speed scanning and how they would react once seeing something like this.

As you all can see, the PIE elevated a huge amount. I honestly did not think it would. I’ve burnt a number of these CMC MAG E01 and all of the high speed scans I have done on these discs resulted in the errors being almost the same or slightly higher, not 50 times greater! :stuck_out_tongue: The jitter was pretty nice on the burn, as were all the other errors, so I have no clue as to why the disc scanned the way it did. Perhaps some other factor we cannot actually measure/test, was out of spec.

Just to make sure it was not a bad disc or something, I will do this:

  1. Scan the disc again at full speed.
  2. Burn another completely different image @4x in the same writer
  3. Test the new burn at both high and low speeds once again.

@ Chas, I will show you soon, why high speed scanning shouldn’t technically show so many more errors on a disc. Just wait for my next post :slight_smile:

@ Franck, you are right that just the odd discs here and there are showing elevated errors at high speed scanning etc and that it won’t just change people’s minds overnight, but I do think if we try showing some good examples wherever we can, it will help to sway the mind’s of some people, perhaps even the reviewers who review the latest DVD writers. Also, I’m going to read your article shortly, should be interesting :slight_smile:

EDIT: I know I’ve said this plenty of times, but the lack of scanning jitter, especially when someone’s drive can do it, is leaving out some of picture. I’ve had a fair share of discs that skyrocketed in PIE errors precisely where the jitter had increased and then also dramatically dropped when the jitter levels suddenly decreased. These particular discs I talk about only showed these characteristics when I used high speed scanning. Just using 4x or 8x without jitter showed some supposedly great burns, which had playback problems in some standalone players.


#19

Alright, well here’s the second scan of the exact same E01 disc. Please note that my mother came into my room and took the liberty to start moving my discs around so it was not a “mess”. Luckily I got home from my gf’s house and stopped her before she wrecked everything. Unfortunately, from piling the discs up like she did, she scratched the E01 disc a little bit :a

BUT, it didn’t really affect it a huge deal. Just some more PIE and more PIF :stuck_out_tongue:

@ Franck, I just finished reading what you’ve written in your article so far. Pretty solid evidence there with all those picky drives and their TRT compared to the 16x scan. Btw, in one of your scan pictures I noticed an elevated level of PIE where the jitter increased. This is something I’ve also experienced in the past.



#20

Alright, here’s the second test disc I just made. Burnt with the 106D @ 4x again. Scanned at low (4x) and high speed (16x). Please note that there were some bits of dust/scratches and whatnot on the disc before burning, I tried to clean it off, didn’t really want to dive into the middle of the spindle and get out a perfect disc to make a useless copy lol.

All I can say is WOW. The results @ 4x without jitter scanning would show a really good burn. With jitter also quite good I must say. 16x scanning just makes you say wtf. The only thing left to do for me is write a third disc with the 106 @ 4x that shows the same errors. I will then watch the entire movie in my PS2. I’ll post later tonight or perhaps tomorrow about how the disc went. :slight_smile:

@ chas, see how in the results summary, the samples are lower in the 16x scan than they are in the 4x scan about 20k less samples. So the 4x scan has gotten more samples and showed a higher level of errors @ 4x than it did at 16x. So basically the Verbatim disc was quite stable/readable at high speeds and since there were less samples, it showed a similar, if not lower/slightly higher level of errors at high speeds. Pretty sure this is why the errors should not increase a great deal on a good disc. If the disc is difficult to read at high speeds, the errors will increase plenty. Please correct me if I am wrong, Franck, Drage :slight_smile:

EDIT: Just so ppl know, TRT on these two CMC MAG E01 is actually perfect in my most fussy TRT drive, the Pioneer 111L.