Avery "Permanent" labels work flawlessly.

John

I believe that the slower the burn the better the copy. I use a DRU500A and burn at 1 x I have burned at 2 x and 1x using Verbatim DVD blanks and I feel I can see a difference in quality. Just my opinion. I know with CDR's burning music there is a difference in compatability with players if you go over 4x some players will not see the music. A technically oriented engineer friend of mine said that in the case of cdr's the slower speeds burn deeper so more players can read the music. The faster speeds burn a shallower track and some players have trouble playing the cdr. I burn my cdr's at 2 x and have never had a problem but at 4x I have had a problem in my own equipment which is a excellent quality Kenwood system. Burning is burning so I would assume that the same situation holds with DVD's

Typically, the slower burn rate provides a "cleaner" burn. This is very much dependent on the burner, and so some burners may burn very clean at the faster rate just fine, while others will not. In addition, some set top DVD players may be able to read "dirtier" burns than others, so you're really talking about two things here: Does the burner burn just as clean at the faster rate, and how important is it that it play on all set top players.

For best compatibility with set top players, burn at the cleanest rate your DVD burner supports (i.e. if a 2x burn is just as clean as a 1x burn, you can use 2x with no worries). Unfortunately, there is no publicly available (and understandable) information on what degredation each burner suffers as the burn speed increases, so the "safest" bet is to use the slowest burn speed.

YOU'RE explanation is somewhat what a person at a retail store told me. They pretty much said that the faster the burn, the less deep the impressions. THerefore, some units have more difficulty reading the less pronounced details.

This being the case, why would anyone ever want to buy a fast burner???. Or the faster media, for that matter.

Brian

My burner is an HP300i. It claims to burn at 4X or less. At what speed is its cleanest rate? Who knows? All I can say is that I have had problems at 4X, but not at 2.4X.

The ironic thing about this situation is that I had the 200i which is a 2.4X unit and just bought the 300i for faster burns. Seems as though I kinda just wasted my money since the 4X speed seems less compatible with set top units.

>>why would anyone ever want to buy a fast burner???.

For DVD's that I make to give to others, I use the slower burn rate and best media I can get. When I make a DVD that only I am interested in watching, I'll use the faster burn rate that I know works with my set top player. In this case, however, I take the chance that others may not be able to watch that particular DVD.

This does make sense, I seem to remember seeing something similar when CD-R was becoming more widespread. I don't pretend that the following represents a scientific analysis but would be most interested to hear from those that might have access to such data:

When a DVD (or CD for that matter) is "burned", the chemical composition of the dye layer is changed. The dye becomes more opaque so that less light is reflected by the reflective layer. Upon playback, these non-reflective areas are detected as "pits" while the unburned areas, reflecting more light, are detected as "lands". The faster the rotational speed at burn-time, the greater the dependence on the rise time and slew rate of the writing laser and associated electronics. If these rates are sufficiently slow, the start of a pit may appear "late" or the end of a pit may be elongated. This equates to bad data at read time and therefore errors. The media itself also plays a role in this. If the thermal characteristics of the dye layer are such that heat is not localized, the pit will be created too large, again resulting in read errors. Also, the amount of light reflected by a "land" varies from manufacturer to manufacturer. The difference in light levels between a pit and a land (also referred to in specifications as reflectivity) will also determine compatibility with players. Very old players are designed to only respond to high reflectivity disks (such as those made by the stamping process). DVDR may not have enough of a differential between reflected and non-reflected light levels to be detected. The "opaqueness" of a burned area does not produce a black body, and some of the light hitting the unburned area will pass straight through it. Plus, elongated pits separated by small land areas may be misinterpreted as simply a long single event.

Based on the above (admittedly possibly rather weak) theory, I would tend to want to burn DVD for distribution at a slower speed than that allowed by my machine (Sony 500A). However, taking other factors into account (such as quality of media, anticipated average age of target DVD players and the fact that I can be one impatient dude), I threw caution to the wind and burned 40 copies of my last project into Memorex 4x DVD+R discs at 4x. That was 3 weeks ago. Only 1 report of failure so far and burning another copy to the same media at 1x did not solve the problem. But burning a Sony DVD-R at 2x did.

YMMV

Andy

Also the use of DVD for data storage for some reason seems tobe fine at the faster rate I guess data is not as critical to the nuances of video.

Actually, data is MUCH more critical. You can drop a bit or two in video and never notice it - in fact the very act of compressing the video for DVD drops lots of bits. That's why it's called "lossy compression".

Drop a bit or two in your data, and all h*ll breaks loose.

It's the player that makes the difference. Set top players are designed for a realatively narrow spectrum of data quality - while the DVD drives used in computers are much better at handling a wide variation in data quality.

that makes sense to me. I use a internal dvd drive DRU500A and use it to back up my hard drive periodically. The dvd never sees anything but this drive. I use verbatim +RW to create a back up of my hard drive every month or so.

Hi All,

When we burn CDR or DVD, the data is recorded into the disk by virtue of changing the reflectivity of the dye layer. The laser is turned on for a finite period of time and hits a small area on the disk. Changing the reflectivity, or phase of this little area creates a level change in the read laser, and through a lot of black magic, the data outupt. Now, having said all that , the laser is turned on for a very brief period of time to burn the dye. The laser beam is a circle, but since the disc is rotating while the laser is on, the area affected on the disc is actually elliptical. The faster you spin the disk when you burn, the more elongnated the area becomes. The more elongnation of the area means that further out from the center of the burn the reflectivity or phase change, is not as great as it is in the center. Some readers have trouble differentiating between an elongnated area and an unburnt area, resulting in read errors. Fixes for this have been better (faster) dyes, which do not "bleed" as much and are more responsive to shorter blasts from the laser. Shorter burn times equal less elongnation because the disk hasn't rotated as far. Also readers have better error correction and optics, so they read better than older (cheaper) machines. No matter track or disk at once, the burn principle is the same, so the theory holds true for anything you do.

Personally I burn audio CDR at 1X on an old Sony Spressa, data CDR at 8x and all my DVD-r stuff at 1x. I think the upper limit of burn speed is dynamic, having to do with the type of media, the target player and the type of data being recorded. But heck, I ain't in no hurry, so I burn slow and leave the physics to the engineers. For people who burn commercially, or have a lot of product to get out the burn speed becomes a relevant factor, and in those cases I would burn as slow as the reality of the situation allows and hope for the best.

Great forum and great people posting. I've learned so much from you folks. Thanks for the knowledge, and thanks for letting me ramble on.



Danny

I've been sending out DVD-Rs of a short trailer of a movie I'm working on, letting the software (DVDA) pick the 2x burn speed. For the actual 'film,' i.e. for projection on a large screen at festivals, maybe I'd better slow it down to 1x.

Fine input from all the SoFo posters. Thanks from all those of us forum members who hungrily read all this wisdom & knowledge.