Altercuno-- No, the rumors were untrue. Chromium dioxide pigment is composed of very uniform crystals that are perfectly shaped, like long glass rods. That makes them easy to disperse in a coating and to align physically on a tape. They are harder than ferric or ferric-cobalt pigments; so a new head with its uneven finished surface loses some of the rough finish when running chrome tape for the first 70 hours or so. That is headwear that polishes the surface. After that, the headwear is extremely small, and the gap stays perfectly shaped. The 3M tape filled the gap with lubricants over time even because there was so little wear. At about 1,000 hours the heads running 3M tape had to be burnished to bring the RF values up to spec, and the burnishing brought the total headwear to a level slightly GREATER than that of heads running BASF that had no drop in RF at all over 1,000 hours because the tape kept the head clean. Other pigments with low headwear eroded the gap over time, and those heads had to be burnished also. So the longest lasting professional VCRS were ones that used either BASF tape or 3M tape. With BASF, though, the RF values stayed constant over the 4,500 to 6,000 hours the heads lasted; and QA people preferred a constant RF over time rather than a drop, burnishing, and a drop again over the life of the heads. All video heads were ferrite. Chromium dioxide on softer heads such as metal or permalloy wore the heads LESS than cobalt-ferric tape. The surface wear was greatest on hard heads. In all cases, the gap stayed pristine over time; and it is the gap distance and uniformity that determines the integrity of the magnetic flux and, concomitantly, the integrity of the recording.
Wow, am not sure I fully comprehended the technical aspects of what Joe had to say but I am sure they meant something to the professional. I, as just Joe Public, wouldnt have known about any of this and had I known or had video magazines of that era told me about the benefits of BASF I probably would have used it exclusively. Its all rather moot now since I have switched over the burning DVD's. Is there something I should know about this media, other than the fact that I have had it impressed upon me the use of only certain media to use (Verbatim, Maxell, something called something like Toyo something, etc.). I dont want to be down the road another 20 years and find out I messed up again or missed out on doing the right thing.
The most important thing to know about DVDs is that the quality of the recording must be good in the first place so that the error rates are low from the start (They creep up over time as the integrity of the marks made by the recording laser deteriorates.) Good recordings mean using good discs, a good drive compatible with those discs, a suitable recording speed, and correct software and computer settings. Taiyo Yuden and Verbatim make good discs that are generally the most compatible with drives (although Taiyo Yuden's recent 16X DVD+R media-late to market-are showing some compatibility problems). There are other good discs on the market that take a great deal of abuse mostly because they are not intially compatible with drives and only become compatible after firmware updates include them after the drives have been on the market and some users have decreed them as "garbage." CMC is a notable example, but they have additional problems in that they appear to sell off-grade product to no-name brands rather than destroy them. People who get less-than-ideal CMC product then assume all CMC products in other brands--HP, Imation, Memorex, Maxell, Philips, TDK, and other--are necessarily poor. CMC actually produces most of the Verbatim DVD product; so they know a thing or two about quality production even if the marketing of off-grade product hurts them. In general, test a DVD brand on your drive after recording it to get an idea of the recording quality. Scans are helpful even if they cannot be relied on for accurate test data. A scan will at least tell you if the disc and drive you are checking are compatible. Look at the bottom surface of the disc after recording to see if black dots appear in places. They indicate either defects in the disc or a bad mark due to transient debris on the disc where the laser creates a "shadow" past the debris. If everthing looks OK, store the disc away from heat and humidity when not in use. Do not use paper labels on the disc. Use a scan to check the discs after 6 months, a year, and two years to see if the error rates remain stable. They will have increased over time, but the increase should be small. If the errors show a dramatic increase at any point, copy the data to another disc. This procedure should guarantee disc information lasting decades.
Thanks, Joe, Very informative and useful information. I usually follow most of what u said and I always scan a burned disc immediately after it is burned. I put the burned DVD in my player and using the fast scan run thru the entire disc. I have caught a few that hung up, re-did them and they came out fine. Altho, I just did THE DEPARTED, using DL Verbatim discs and it played generally fine, hanging up in a few places and skipping about 5 min each time before it started up again. I wrote it at 8X using my Roxio software since I cannot get CloneDVD2 to work using any DL media. I have posed this question a few times both on here and the SlySoft Forum but have found no corrective response. Has anybody out there had problems with CloneDVD and DL? Or run into the problem I have described elsewhere in this forum (or was it the Slysoft one?) about the media not being large enough to hold the written movie. It has me stumped and perhaps others as well since everyone seems to have given up on trying to figure out why the problem exists. I have taken screen shots of each CloneDVD screen as I loaded and burned the movie to show exactly how I have the settings but I cant figure out how to get those pics in a forum thread so that others could see exactly what I have done and perhaps offer me some help. Anyone know how I can accomplish that? I presently have the whole story in Word document complete with the screen pics. Thanks to all out there for any assistance.
