Medium type and quality


I tried google, and forum search but didn’t found anything about this …

Is Medium Type related to “quality” ? …I saw lot of people ask about ‘best for my drive’ …

I’ve used some Ritek (labeled Samsung 32x) CD-Rs, and reported by cdrecord (I use linux =) ) was :

Disc subtype: Medium Type A, low Beta category (A-)

I purchased another CD-Rs (labeled Samsung 48x), and manuf. was Prodisc … and :

Disc subtype: Medium Type C, low Beta category (C-)

I know that “Samsung” is only “letters printed on top” and already know what means low/high beta (reading BoSkin posts ;o) ) … but about Medium Type ? … it affects ‘quality’ ? for example, my previous CD-R (Ritek – 32x) was better than those newer ones (Prodisc - 48x) ?

Thanks !

Originally posted by diem

Is Medium Type related to “quality” ?

Yes, Disc Grading System :wink:

Originally posted by BoSkin
Yes, Disc Grading System :wink:

So you mean if ATIP tells medium type A, is a GRADE A (according with link above) media ?
the text in that link sound as ‘Grade A’ was kind of rating given by that specific equipment (showed in the picture of your post). Not simple as medium type A (in ATIP info) = Grade A … =)

Thanks again ! =)

Nobody has ever demonstrated any correllation between the grading on the ATIP, and actual write performance. The ATIP is on the stamper itself, and does not usually tell the whole story about the dye or disc quality.

IS ATIP info (Medium type) just info to CD-Recorder write data with ‘proper settings’ ?

If is related to grade, why a manufacturer would label it’s products as ‘low grade’ ?

If I got it right, medium type is only an info used in recording process, not media quality … ?

:confused: :confused:

Originally posted by rdgrimes
Nobody has ever demonstrated any correllation between the grading on the ATIP, and actual write performance.
Hehe, correlation can only approach -1 or 1 and is therefore weak or strong (or neutral = 0). You mean relationship :bigsmile:

Disc Grading System

There are five different grades covering a wide range of performance: A, B, C, D, and F.

This feature provides a means of instantly evaluating a disc without looking at the individual data.
Here are the criteria used to determine the GRADE.
These criteria are somewhat arbitrary, but reflect generally accepted practice in the industry .

GRADE A = AVE BLER over the whole disc less than 6

GRADE B = AVE BLER over the whole disc less than 51

GRADE C = AVE BLER over the whole disc less than 101

GRADE D = AVE BLER in all ten second periods is less than 220

GRADE F = AVE BLER in any ten second period is greater than 220 or Track Loss

QA-201 Instruction Manual


(sorry if I didn’t got … my english isn’t that good :wink: )

So medium type written in ATIP is this grade gauge ?


Originally posted by diem

So medium type written in ATIP is this grade gauge ?

In short, yes.

ISO Standard ISO/IEC 10149, and the Philips Red Book and Orange Book Part II contain more than fifty physical, optical, and electrical quality requirements that CD-R discs must pass. None of these Standards define grades such as A, B, or C.
Such grades are determined arbitrarily by manufacturers. Grades can vary between vendors, and may change with time .

Manufacturers may sort optically scanned discs into Grade A discs that pass, Grade B discs that have few visual defects, and Grade C discs that have more defects.

Although Grade B or C discs may function, they probably do not meet visual defect requirements of the Standards. Successful interchange and longevity is not predictable for such discs. When discs have been graded only for visual quality, even Grade A discs may not meet all other requirements, such as radial tracking (push-pull) and jitter, that must be satisfied to assure interchange and longevity.

CD-R grading systems are not useful for quality purposes.
First, grade specifications are not consistently defined, and are meaningless for brand comparisons.
Second, grading systems based only upon visual defects ignore other critical quality requirements.
Third, lesser grades imply media defects, and should never be used when interchange and longevity are important

Manufacturers who use grading systems may be forced to do so when quality is low. Instead of scrapping rejects, they can be reclassified into lower grades and sold at discounted prices. CD-R buyers concerned about quality should seek manufacturers that can consistently supply media that satisfies all quality requirements of the Standards. Low priced grade B or C discs may be expensive in the long run when duplication and user problems appear.

Originally posted by diem

(sorry if I didn’t got … my english isn’t that good :wink: )

So medium type written in ATIP is this grade gauge ?

thanks [/B]

Just to put my experience in here. The disc grade reported in the ATIP has to my experience NOTHING to do with disc quality.

A disc with “C” in the ATIP may be just as good or better than a disc with “A” in the ATIP.

Most AZO / Cyanine discs is “A” while very many phthalocyanine discs is “C”.

I’ve yet to find a good source for explaining what the “A” “B” and “C” grades in the ATIP really means. Yes there is also quality grades from A to D but this have nothing to do with the grade in the ATIP to my experience - the quality grade is defined after/while the media is made and is not found anywhere in the ATIP.