DNG as an archival format

I back up onto hard drives, and periodically I plan to find a way to "shake the bits around" on the drive to make sure they don't lose their charge over time.

The other issue I have with DVDs is the time factor. I do everything in batches, so I might have a dozen weddings worth of images (50GB give or take) to back up at a time. To backup to DVD you need a dozen DVDs (one per wedding it's unworkably combining them), you have to create the DVD for each one, and feed it into the PC. It all takes time. With hard drive you just drag and drop.

Rare be me to comment on a Tim thread, but...

There is nothing special about .dng. It is just another of many competing RAW formats with strengths and weaknesses.
One archival workflow hangup with .dng is Canon's DPP software is sometimes the sole RAW converter that interprets WB correctly on conversion under difficult mixed light shoots. Also, for some shoots, a single Picture Style results in speedy life-like conversions where other converters need too much effort. While my converter-of-the-month is PSCS3 ACR 4.1 because of its stellar capture sharpening and other enhancements, there are times when ONLY DPP gets the image right faithfully.

If one archives as .dng, embedding the .CR2, the file size is larger than either alone, and the "extraction" of the .CR2 for future processing as Canon makes continuous converter improvements is time consuming, slow, and folder-based.

I think Canon does not get enough credit among for the backward compatibility DPP and Picture Styles provides users with D30, D60, 10D RAW files, etc.

So, then the only reason to archive as .dng is to be able to "view" a file thumbnail with RAW adjustments (because the .dng JPEG is updated) and because one can embed metadata in the .dng without modifying the .CR2.
Well, products like Lightroom and Aperture make the first reason fall, and Canon now allowing software vendors to "write" to the .CR2 (previously Nikon .NEF allowed this but Canon did not without using their SDK) makes the second benefit fall.

I tried .dng for few months and gave it up. Just nothing special with that engine under the hood...
Just my opinion, FWIW... Jack

J Rabin wrote in post #3375662
Rare be me to comment on a Tim thread, but...

There is nothing special about .dng. It is just another of many competing RAW formats with strengths and weaknesses.
One archival workflow hangup with .dng is Canon's DPP software is sometimes the sole RAW converter that interprets WB correctly on conversion under difficult mixed light shoots. Also, for some shoots, a single Picture Style results in speedy life-like conversions where other converters need too much effort. While my converter-of-the-month is PSCS3 ACR 4.1 because of its stellar capture sharpening and other enhancements, there are times when ONLY DPP gets the image right faithfully.

If one archives as .dng, embedding the .CR2, the file size is larger than either alone, and the "extraction" of the .CR2 for future processing as Canon makes continuous converter improvements is time consuming, slow, and folder-based.

I think Canon does not get enough credit among for the backward compatibility DPP and Picture Styles provides users with D30, D60, 10D RAW files, etc.

So, then the only reason to archive as .dng is to be able to "view" a file thumbnail with RAW adjustments (because the .dng JPEG is updated) and because one can embed metadata in the .dng without modifying the .CR2.
Well, products like Lightroom and Aperture make the first reason fall, and Canon now allowing software vendors to "write" to the .CR2 (previously Nikon .NEF allowed this but Canon did not without using their SDK) makes the second benefit fall.

I tried .dng for few months and gave it up. Just nothing special with that engine under the hood...
Just my opinion, FWIW... Jack

Jack, when did this happen and do you have any links for the info? Are there any third party software programs that write to the CR2 or is it only DPP (if any currently)?

One very good reason to use DNG would be to loose the XMP files, and get updated thumbs (for instance in iView).
One even better reason not to, is DPP won't do DNG files.

If it weren't for the latter reason, I'ld be using DNG...

Only programs I have that I know that will write into a CR2 file, is iView. (and DPP off course).

So,

If using DNG in LR there are no .xmp files?

EOSAddict wrote in post #3376010
So,

If using DNG in LR there are no .xmp files?

Correct. Although there are no XMP files anyway if you use the database to store your edits.

In2Photos.
I am not a software engineer, so take this with a grain of salt.
BreezeBrowser enabled writing to Canon RAW for years, likely because they were an early Canon SDK licensee.

In late 2006 or early 2007 +/-, iView Media Pro version 3.1.x QUIETLY enabled writing IPTC metadata into the Canon .CR2 directly. iView was not comfortable, with hype promoting "non-destructive" RAW editing by Lightroom or Aperture, and maybe not wanting to be accused of or risk corrupting a RAW master. But, iView users wanted it and the company quietly put it in.

From inside any DAM application, I want the simple freedom to right-click launch into whichever RAW converter I think renders the most faithful image to the task, so while Aperture and Lightroom have all-in-one feature appeals, they are captive database-converters, and hence not for me.

Because iView lets me write IPTC directly to the Canon .CR2, it has remained my database of choice, and the metadata goes with the .CR2, where ever that .CR2 goes.

Nikon always permitted writing to .NEF files. I suppose Canon was cautious about file corruption, but I've had no problems writing to Canon RAW from iView. There is a difference if you are writing to older .CRW files.

I am not sure what the status is with other leading DAM applications like PhotoMechanic or Extensis Portfolio. You'd have to ask them directly.

Hope that makes sense and helps. Jack

One nice thing (linked to) on the bottom ofthis rather long read:
"Canon Consumer Imaging Group Director Chuck Westfall presented the camera vendor perspective. Mr. Westfall compared two possible solutions for raw data; proprietary and open standards. While making it clear that Canon intended to keep its RAW data recording methods proprietary, Mr. Westfall stated that Adobe's DNG file format has excellent features for archival storage and added that Canon might consider the possibility of adding DNG support in future versions of RAW image conversion software"

I've never used DPP so that's not an issue for me. I like the idea of DNG because it embeds the RAW camera data, with lossless compression, along with instructions that describe how that data's read. This means that in 20 years if software can't read the 20D RAW format from the CR2 file, there's a much better chance it'll be able to read the DNG as it has instructions embedded.

Personally I don't have a problem with xmp files, I don't see what they're a big deal to people. I use Bridge exclusively to work with my RAW files, it shows the images but hides the XMP files.

tim wrote in post #3378346
I've never used DPP so that's not an issue for me. I like the idea of DNG because it embeds the RAW camera data, with lossless compression, along with instructions that describe how that data's read. This means that in 20 years if software can't read the 20D RAW format from the CR2 file, there's a much better chance it'll be able to read the DNG as it has instructions embedded.

Personally I don't have a problem with xmp files, I don't see what they're a big deal to people. I use Bridge exclusively to work with my RAW files, it shows the images but hides the XMP files.

As long as you stay within Bridge you are fine, but as soon as you go outside of that for any file movement, you are screwed. I know, been there, done that. Wasn't fun to fix.

I find it quite useful for the CR2 files to keep their original timestamp, even though the information is in the EXIF, so i'd prefer not to have my metadata embedded. I also don't want a central database, because then if you lose that you're stuffed. XMP files are the best solution for me. For someone who uses multiple programs embedded the metadata would be helpful. I guess it's best to pick one program and stick with it.

In LR, if you turn on XMP files does it write the changes ONLY to the XMP file or does it still keep the info in the database too?

EOSAddict wrote in post #3380695
In LR, if you turn on XMP files does it write the changes ONLY to the XMP file or does it still keep the info in the database too?

It keeps it in both places.

rfreschner wrote in post #3381229
It keeps it in both places.

I thought (hoped) so - just wanted to check!