Convert to DNG in Lightroom? Or keep the CR2?

Pros and cons please. I have been doing this for the past couple years I've been using Lightroom without really questioning it. I don't have any complaints so far but don't really know any better.

There are dozens or hundreds of threads about this. Personally I work with original raw and keep that and a dng copy for archive. If I had to use high MP cameras I'd keep the original but convert to resized DNG (say down to 20MP) and work with that mostly, but when you resize down a DNG it becomes half baked, which is why I'd keep the full RAW. If you don't compress/resample the DNG you get the original raw data.

I don't get the point of DNG. Adobe sells it as 'forever compatibility', which makes no sense to me. I have LR 5.7, DPP 3.n, and DPP 4.n now, which all work with every Canon camera currently on the market. Does someone plan to sneak into my computer and remove the current programs? Or send out a firmware update for my cameras that makes them incompatible? Sure, maybe someday Adobe will stop supporting new Canon cameras. At that point Adobe will go out of business. My old software will still be compatible with my old cameras. DNG makes no sense at all to me.

Well IDK if 20-22MP cameras counts as a high MP but with 36-50 being the new 20 my guess is no

I don't think I'm compressing. Looking in Finder, it seems files from my 6D are about 20-25MP.

Silver-Halide wrote in post #17580744
Well IDK if 20-22MP cameras counts as a high MP but with 36-50 being the new 20 my guess is no

I don't think I'm compressing. Looking in Finder, it seems files from my 6D are about 20-25MP.

Compressing? Why? Storage space is cheaper than dirt. Computers are fast enough now, and getting faster. I would say you are throwing away data for no apparent gain. Why not save a ton of space by shooting JPG, even consider using one of the smaller JPG options? I have literally over a thousand raw shots of my cats. Even if all of them were raw, they would consume roughly 1% of a 2TB HDD.

Both CR2 and a regular DNG are losslessly compressed. On average the DNG compression produces a slightly smaller file, but there is no loss of resolution or tone data (the only image data in a Raw). Some of the more obscure metadata in the CR2 Maker Notes or items in the Maker Notes that Canon chooses to hide or encrypt may not be copied over to the DNG, but for the most part all the metadata comes across.
There is also the option to make lossy compressed DNGs, that are smaller in file volume (MB) because of the compression but not in resolution (MP), but that has to be selected in Preferences. I don't know how to make the reduced resolution DNGs that Tim refers to, but I guess it must be possible because LR's Smart Previews are lossy DNGs with a maximum long side of 2560 pixels. My guess is that they are demosaiced and then downsized, but remain in linear space.

Until now I have used DNG for my work images and kept the backups in CR2, not because of considerations of "future-proofing" or space saving, but because LR/ACR Quick Load data can be embedded in the DNG, which replaces the program's need to write and/or read the data to or from the CR Cache folder. However, my laptop is starting to show its age and is overheating while converting large numbers of CR2s during import and LR6 makes it worse because instead of converting each CR2 and then writing the DNG to disk, it first writes all the CR2s to disk and then converts them to DNG and writes over them. So, I guess it is back to CR2 for me.

I have been using LR4 since it was introduced, and always just stuck with the CR2 files. In the early days of .DNG file support for non native .DNG files in non Adobe programs was questionable, so it put me off the idea of converting to .DNG if they might have issues in applications that generally supported CR2/CRW files nativly anyway.

After trying LR6CC I now have some .DNG files, I did some RAW panoramas, and they produce .DNG files. I was pleased to see that I could import them into my old LR4.4 Libary, so they are back compatible. I have also been playing around with ML and Dual ISO on my 50D. The last airshow I shot with Dual ISO for every other shot. Those Dual ISO shots will also require processing that will create .DNG's. I shall keep the original .CR2's for all of the images though. I will only be converting the Dual ISO files to .DNG.

Alan

GeoKras1989 wrote in post #17580742
I don't get the point of DNG. Adobe sells it as 'forever compatibility', which makes no sense to me. I have LR 5.7, DPP 3.n, and DPP 4.n now, which all work with every Canon camera currently on the market. Does someone plan to sneak into my computer and remove the current programs? Or send out a firmware update for my cameras that makes them incompatible? Sure, maybe someday Adobe will stop supporting new Canon cameras. At that point Adobe will go out of business. My old software will still be compatible with my old cameras. DNG makes no sense at all to me.

The fundamental premise of DNG is that CR2 support can one day vanish for the 20D (for example), because Canon left it behind as too archaic to anyone wanting to actively use it any longer.

Therefore the response is, "Why don't you convert to the Adobe 'forever format' DNG to avoid that obsolescence issue?!"

One might then challenge, "But what about Adobe ceasing to exist as a company?! Then what, if all your files are DNG?"

To which someone responds, "But it is likely that a lot of other companies continue to exist who DO support DNG even after Adobe ceases to exist."

But then one might counter with, "But it is likely that other companies continue to exist who DO support CR2 for the 20D, even after Canon ceases to support it."

To which someone says, "But continued support for generic DNG is more likely than continue support for ONE specific (20D) version of CR2". And BigAl007's recent post bears out that approach, "I did some RAW panoramas, and they produce .DNG files. I was pleased to see that I could import them into my old LR4.4 Libary, so they are back compatible", although in this case he was using an older version of Adobe software, not an independent company's software.

Lastly comes one last realistic assessment, "if all your data is not continuously moved from today's harddrive to tomorrow's storage device, one risks the loss of access to ANY of this data, regardless if it is stored as CR2 or DNG!" For example, any data sitting on an old ST-506 harddrive has the challenge to the owner of, "What interface board supports the old ST-506 when using the current PCI buss motherboard PC so I can even get at the data on the ST-506 harddrive today?"

My own approach is to store in CR2, and if Canon ever abandons support for the 20D or 30D, then I will take the steps to converting all those CR2s to some format (DNG or otherwise) which assures continued reading of the old cameras' data, just as I will make some efforts at moving data from one storage device to another one more contemporary to the times. Different approaches for different folks!

Wilt wrote in post #17580899
The fundamental premise of DNG is that CR2 support can one day vanish for the 20D (for example), because Canon left it behind as too archaic to anyone wanting to actively use it any longer.

Therefore the response is, "Why don't you convert to the Adobe 'forever format' DNG to avoid that obsolescence issue?!"

One might then challenge, "But what about Adobe ceasing to exist as a company?! Then what, if all your files are DNG?"

To which someone responds, "But it is likely that a lot of other companies continue to exist who DO support DNG even after Adobe ceases to exist."

But then one might counter with, "But it is likely that other companies continue to exist who DO support CR2 for the 20D, even after Canon ceases to support it."

To which someone says, "But continued support for generic DNG is more likely than continue support for ONE specific (20D) version of CR2".

This makes no sense to me. If my current version of LR works NOW on my 60D/6D/G15/260HS, how does Adobe not supporting those cameras in the future have any bearing at all on how my current version of LR works? Sure, they can stop supporting cameras in future versions. LR 5.7 will ALWAYS support the cameras I have now. The CR2 obsolescence issue is a red herring. If Adobe stops supporting Canon cameras, Adobe will become irrelevant. Whatever file format they have will go away with the company. DNG may well be useful for HDR and Panos, but that is internal to Adobe programs. Lots of other software is available to do those things. DNG offers nothing outside of the Adobe platform. So far, it never has. I can't see how it ever will.

GeoKras1989 wrote in post #17580906
This makes no sense to me. If my current version of LR works NOW on my 60D/6D/G15/260HS, how does Adobe not supporting those cameras in the future have any bearing at all on how my current version of LR works? Sure, they can stop supporting cameras in future versions. LR 5.7 will ALWAYS support the cameras I have now. The CR2 obsolescence issue is a red herring. If Adobe stops supporting Canon cameras, Adobe will become irrelevant. Whatever file format they have will go away with the company. DNG may well be useful for HDR and Panos, but that is internal to Adobe programs. Lots of other software is available to do those things. DNG offers nothing outside of the Adobe platform. So far, it never has. I can't see how it ever will.

I did NOT raise the issue of ADOBE 'not supporting those cameras in the future'...I used the example of Canon wanting to drop support for CR2 for 20D or 30D in its own software. But what guarantees that Windows 10 or Windows 25 128-bit can even load and run LR3 32-bit or LR5 64-bit in the future? If they do not run, then what?

I don't do things unless I have a good reason to. I guess I never saw a good reason to convert to DNG. I keep the CR2 for all images that I considered good enough to convert to 1024ppi (long side) for web viewing, or for prints (and I store those JPGs as well). As mentioned, storage is cheap. If the day does ever come that CR2s (and/or DNGs) are no longer with us, at least I've got something. If CR2s, DNGs and JPGs become obsolete before I convert them to some other future format, I still have prints.

Lots and lots of prints

As the bard famously stated, " Ain't nobody got time for that!"

Not all raw converters support all DNGs. It makes no sense to delete the original raw file that you actually think is worth keeping. DNG is a flexible format and documented and probably the most widely used "neutral" file format but, most of the time, it is a solution looking for a problem to solve. In the millions of threads about this topic, I'd like to see an accounting of how many people have suffered at the the hands of raw file obsolescence that DNG could have avoided if the raw were converted at the time of download and the raw file deleted permanently.

My guess is approximately 0.0 accounts would surface.

For more "best practice" discussion on archiving raw files:

http://www.dpbestflow.​org …rmat/archive-file-formats

If your raw file format gets phased out, but was supported by Adobe's DNG Converter, my hunch is you can convert your raw files as needed when the raw file phase out apocalypse occurs.

kirk

I convert mine to DNG. The only time I've ever wanted the CR2 back was in a thread here on POTN, discussing how different raw converters might handle a difficult-to-process file.


I can't worry about future obsolescence of DNG or CR2 files yet; I'm not finished worrying about the obsolescence of all my 3.5" and 5.25" floppy disks. All things in due order.

nathancarter wrote in post #17581019
I'm not finished worrying about the obsolescence of all my 3.5" and 5.25" floppy disks. All things in due order.

Boy, I remember those
And I still have some 3.5" disks along with an external disk drive that I can use.