photos onto a RW CD

[Rob A]

hey guys, ino this is KINDA of topic, but it is for my photos! i was wandering how many times a rewritable CD can be erased? can you keep using them again and again? thanks for any help!!

 

[Ant]

1000 times.

 

[Rob A]

cool thanks!!

 

[Kent Frost]

I hate rewritable CDs. They seem so unstable. Perhaps its my burner, I dunno. But everytime I try to erase then reuse, the disc becomes trash.

 

[DavidGeorge]

I guess... as many as you want??

 

[Johnboy2978]

Like Ant, I think 1000 x's is the industry response as to how many rewrites one is typically good for. As with anything else though, you would be wise to have anything important in more than one place to make sure that you don't lose it (e.g., hard drive, thumb drive, another cd, etc).

 

[Ant]

I guess... as many as you want??

If you want 1000 or less then, yes, you're correct.

 

[Rob]

I am, as ever, going to disagree with some of the above posts! Not to be difficult you understand, just because it's my opinion.

From my direct experience with the technology involved as an IT consultant, I understand that there is no number for the answer to this question without more specific details and controlled tests.

Re-writing and writing to a CD-RW is more flawed than either a commercially produced CD or a CD-R. The reason for this is that the CD is only slightly burned by the drive. A commercially produced CD will have the layer of shiny metal (usually aluminium based) burnt entirely through. A CD-R will scorch a heavy mark on it. A CD-RW will scorch a slight mark and then subsequently attempt to erase it. Quoted manufacturers' estimates are based on optimal situations with controlled environment which you will not realistically achieve at home.

The actual answer is going to be dependent on the CD-RW media you purchase and the CD-RW drive you use. You are, to a great extent relying on luck with this technology and the results will vary from disc to disc. Some discs will be inoperable after one RW and some may last for quite a long time. I would wager, with confidence, that nobody in a domestic situation could make a CD-RW work for 1000+ iterations.

To guess your motive for asking this question, I would recommend not using CD-RW technology for anything more than incremental backups. Depending on the number of photos you take and their value to you, I would recommend using CD-R for weekly or monthly backups. If the photos are extremely valuable, then consider using multiple backup media such as a separate computer or tape drive. FTP the images to a third party for extra assurance as well.

This sounds a little OTT, but assuming you have a friend with a computer who is vaguely reliable, I would suggest swapping CD-R discs with them on a weekly or monthly basis. Copy each others' data from the CDs to your HDD and you'll both be safe as houses in the event of a nasty HDD crash/failure.

 

[Ant]

I think you have valid points but I also think you're exaggerating the problems.

I was in correspondance with OSTA (Optical Storage Technology Association) a few years ago because the company I worked for wanted to go to an optical storage archive system. I did a project study on this.

This number of approximately 1000 rewrites (OK I should have said approximately in the first place) is an official OSTA figure. Now they're a pretty realistic bunch, and if you ask them other stuff like shelf life of a CD-RW they'll give you a fairly wide ranging figure and tell you that it's quite dependant upon manufacturing quality of the disk and the writer etc. But they seem to think that this figure of approximately 1000 rewrites for a CD-RW is a pretty hard and fast one for any CD-RW, or at least a more reliable figure than, for example, shelf life.

Of course many people will tell you stories of disks that weren't useable after a couple of writes, but then many people will tell you horror stories about failures on their Canon 20D or Nikon D70. Technology isn't perfect and failures happen, but that doesn't mean that the whole system is inherantly flawed.

I'd say the average home user has more chance of getting 1000 rewrites on a CD-RW than not.

 

[Rob]

I now expect you to back up your argument by performing testing to destruction on a realistic sample of say 20,000 media of various manufacturers. Shouldn't take you too long