In his Lightroom 2 book, Martin Evening writes that "The DNG file format...has been widely adopted as a preferred format for archiving raw camera files". Saving images as both CR2 and DNG files obviously takes much more disk space, but I'm new to post processing and do not know enough to understand if I would be making a mistake by not also saving the CR2 files. Would I be giving something up in future processing or anything else by saving only as DNG?

Any guidance would be appreciated.

You lose the ability to use the camera makers software. If this matters to you then you get to keep the CR2's around. If it doesn't then convert away.

Do not delete the CR2 files.

You will have no longer access to Canon's own RAW processor DPP, and also no access to Capture One Pro, another first class RAW processor.

I follow the "disk is cheap and getting bigger" school. I use XP. When I import I use the option to make a backup at the same time. I do this directly to an internal drive reserved for backups, this gets me the CR2 squirreled away should I ever need it. I convert to DNG on import.

The LR library and catalog get backed up every night to the backups drive. After significant changes I sync up with an external drive on another system (a Mac Mini so that I don't get hit on both systems by some weird Windows problem). Well, actually a pair of drives . I have a USB drive I sync up to sporadically as well.

I also use Carbonite to continuously backup the library to their online backup service, which has the handy feature of being unlimited storage.

Yup, I'm paranoid. Then again, if the house burns down I'm still covered. I see it as one of the benefits of going digital.

cheers, martin

Ok, then let me ask if there are real advantages to working in DNG? If DNG files will not be recognized by DPP, Capture One Pro and other processors, maybe I should just work in CR2 and forget DNG?

Martin, of course you are right that disk space is relatively cheap and getting cheaper all the time. But it is still not free ( dollars, maintenance time, replacement) so if I am not going to be using both types of files I would rather simplify my life. Between switching from film to digital and Windows to MAC it sometimes feels like I am in learning overload anyway.

No sidecar files.

You can fit a BIG preview in it.

The archive copy can be kept as a RAW file whilst the initial working file can be set up as a DNG. With the increasing use of Lightroom/ACR type non-destructive images, I would suggest that we are likely to store fewer Jpg/Tif/whatever files than previously; only creating them as required. This means less storage perhaps?

anthony.

If you save as a Smart Object in a TIFF you get all the sidecar stuff, as well as any work. You can always extract the original RAW file too.

I'm just sayin.