Hi Franz Do you realise that these two articles have tested different drive models? Every model from a given manufacturer (and even each unit!) scans differently. So it doesn't make much sense.

Besides, the great aspect of Dee's article is to explain very clearly (IMO) that this search for an "accurate" scanner (= close to CATS, because as DrageMester and Dakhaas explain above we-are-not-measuring-errors-on-a-disc when scanning) is vain, and even totally useless.

Scanning with end-user drives has only one 100% legitimate use which is to compare discs/burns. Disc/burn A scans better than disc/burn B. Period. Our end-user drives are too unreliable scanners for any other purpose, without extensively comparing burns first. When you've done lots of comparisons with a given scanner (and I mean unit), then you can start drawing significant conclusions about the "absolute" quality of your discs, not before. Put differently, get to know your scanner (as long as it's consistent and not too looney), it will be far more useful than trying to find a drive manufacturer/model that would be more "accurate". If a cheap burner out there could approach the precision of CATS, do you think the big companies would need CATS?

I'm more and more suprised that this quest for "accuracy" keeps on constantly popping up, after all the discussions that take place at so many sites (and very extensively here at CDFreaks - see links hereunder ). This is an irrealistic, unsound approach to scanning with end-user drives.

Must reads:
http://club.cdfreaks.com/showthread.php?t=185916
http://club.cdfreaks.com/showthread.php?t=163379
http://club.cdfreaks.com/showthread.php?t=167693
http://club.cdfreaks.com/showthread.php?t=167758

Have fun!

Here's an example where a Liteon seems less 'neutral' towards a disc than a Benq, although the burn was done in a Benq. Fortunately I usually have found both the Liteon and Benq to be fairly neutral in their scans, only when the Benq encounters high jitter levels has it ever given false results from what I've seen - perhaps there is a similar issue occuring here where the Liteon has sensitivity to a disc that it perceives to have high jitter levels (accurate or not)? The 4x Liteon scan is in extremely close agreement to the Benq scan in regards to PIFs, but the PI levels are quite inflated (jitter related?). The 8x scan shows a larger density of PIFs and the PI levels are grossly high (a 16x scan in the Liteon is close to the 4x result).

@ dakhaas & Franksoy
I apologize for not being realy able to follow the discussion at the level you put it.
Thanks anyway for your answers and any futher explanations


@ Franksoy
We need to have your opinion about the little discussion we have here:
http://forum.gravure-news.com/a-la-r...l--vt23536.htm

Sorry if you felt I was kinda condescandant, Franz. I can be a pain in the a** sometimes.

[OT]
I've input some preliminary comments

[/OT]

I wouldn't worry too much Franz

Thanks for people being nice with me ...
I think I need to understand what this discusssion is really about
before asking something again.

Everyones input is valid and welcome, just as everyones opinion is valid about PI/PIF scanning.

The article probably won't bring a great deal of help to the users who are already very knowledgable about media and PI/PIF scanning. The article is more aimed at members who are perhaps new and learning about PI/PIF scanning. The hope is the article can help show what members can expect when they use the tested drives for PI/PIF scanning.

That's a fair statement.
It is a good primer to get your feet wet.
As people become more knowlegable and aquire a better understanding they will inevitably draw their own conclusions, as they should.

At the present state of discussion I have to ask something:
I use take in consideration these tests called « correlation tests » that you can find in some reviews of recent burners.
In these tests they compare how the burner reviewed and the CATS report the sanning errors:
they compare the trend more than absolute values.


For example here is what you can find for 2 of the « good scanners » after Dee’s article:

Plextor PX-760A:
« PX-760A vs CATS - Page 1, 2, 3 & 4 »
http://www.cdrinfo.com/Sections/Revi...6587&PageId=19
The conclusion of each of the 4 pages:Lite-On SHW-16H5S (firmware LS0W)
http://www.cdrinfo.com/Sections/Revi...5954&PageId=19
Conclusion of each of the 4 pages :So could know somebody explain to me
if these correlation tests are of any value in order to decide if a scanner is better than an other one or not ?
In other words may I use a burner that has a bad correlation test
as well as a burner with a good correlation test ?

@Dee

If your Lite-On drive is supported by DVDScan, would you choose some of those discs with large jumps in jitter at the re-linking points to scan jitter comparatively with the BenQ and the Lite-On at a few speed settings, provided that you don’t mind retracting some of your previous conclusions?

muchin, I have not changed my mind about how PIE/PIF relate to a disc since posting the metaphor you're referring to. In that post I was trying to fight the idea that the reading drive is *entirely* to blame for PIE/PIF, and in this thread I'm just saying that the media is not *entirely* to blame for PIE/PIF.

There may very well be problems inherent to a disc that will show up in scans on any drive (that reports truthfully), but those problems can not be expressed as a precise number of PIE/PIF because those are not on the disc per se but occur as a complex interaction between drive and media.

To use a new metaphor: In order to keep a car on the road, you not only need to avoid going into the ditch on the right hand side of the road - you also need to keep the car from going into the ditch on the left hand side of the road. Depending on which ditch you're heading into, you need to steer the car in the opposite direction. I'm trying to do the same with discussions about PIE/PIF scanning,

Drage

I should have provided the link for those who are not aware of it. It's good that you have done so.

@muchin
I am unable to get DVDScan to work on this system, i'm not sure if the SHW-16H5S is supported in any case.

Here's another example where the Benq seems to be the much more neutral of the two drives when comparing a Liteon and Benq scan.

i don't understand this statement. what do you mean by 'neutral' ?

What I mean by that in these circumstances is when one drive appears to have a greater sensitivity to the effects of such things as a shift in jitter levels, calibration points, etc. In the example linked, the Liteon scan appears to go nuts between two of the calibration points and in all likelyhood isn't giving a realistic representation of the error levels existing at that location on the disc. Perhaps a large jitter shift would show if a jitter test was performed on the Liteon using DVDScan, I do not know. Similar problems often occur where Benq drives report exaggerated error levels when jitter levels reach high levels (roughly 12%+).

fine but this is not how the word is used in the article.
anyway your usage of 'neutral' is unnatural IMO. perhaps 'robust' would've been better ?

I disagree, I'm simply being more specific as to what causes a drive to report errors in a less 'neutral' manner, i.e. jitter levels, calibration points.

All my Imation/MBI look like this from the respective drives. Only the Benq won't burn them above 2,4x. The TRT isn't from same disc as QS but TRT with my LG always look like this (still it's a Imation/MBI from about same day). Only my Benq can hardly TRT any disc. Either all my burns are bad or my Benq is a bit off. I believe the last and will replace the Benq next week - for another LiteOn or LG. (Don't know about other ppls Benq drives but mine has been "special" from the start. Does burn perfect on T02/MCC004 quality media but that's all)

CJ2, I have seen a handful of other people over the past couple of years that have gotten Benq drives that were defective and behaved in just the same manner as yours - they had similar scanning behavior and had varying burn problems. I have to ask, why didn't you exchange it since your drive is defective? As you probably know from the number of Benq fans, the 1640 is a great burner, unless of course it's defective as yours is...

Correct. The word Neutral is being taken out of context.

Sorry, after more closely reading your intentions for the term 'neutral' I am not quite using it in the same manner. Maybe it would be better to describe my example(s) as a scan that is 'falsely influenced' rather than less 'neutral' by factors such as jitter levels or calibration points vs. a scan from another drive. Factors such as those are what create 'biases', such as the influence that high jitter can have on the ability of Benqs to report errors in reliable levels.

I've had worse drives in LiteOn 411 and 811 and perhaps NEC 3520 & Pio 107. I was sure my Benq was just less good because the 1640 seemed to be made in Taiwan or China (as far as i remember) and one was better than the other. When i got it it was mainly for jitter testing (curiousity) and because of all the good reports. I now think there's something fishy about all the perfect Benq scans and atm i don't trust Benq drives. Perhaps i'll return later as i did with LiteOn

(Just ordered a Pioneer 111 btw)