Backing up RAW files using the export and burn to cd functions in Lightroom should have a slight modification from backing up TIFFs or JPEGs.
The RAW format from digital cameras is different between many of the manufacturers. Adobe created an open source standard called a Digital Negative format or DNG.
When backing up RAW images from my digital camera, a Leica DLux 3, I use the same settings as for TIFFs or JPEGs, but instead of choosing the file setting of Original, I choose DNG. Some new options are available when making this choice.
As the image above shows, you can choose to compress the image and add the original raw file. I use the compression because it is lossless and I choose not to keep the original RAW file. Your choices can be different and I would love to hear what others use.
The point is, choosing an open standard, especially if you believe in Adobe's digital imaging products, is good for the future of your image. Adobe has a history of keeping open source compatibility for a long period of time - look at the PDF or Acrobat file structure for proof of this claim.
I have a separate setting saved for backing up RAW files to DNG based on these settings.
NOTE: Here is an article from Adobe on the DNG standard they created and an article from NikonDigital.org also on the DNG standard.
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