# Thoughts on DNG



## woollybear (Apr 10, 2012)

I'm interested in folk's thoughts on Adobe's DNG...

Is there any loss of information converting back and forth from Canon's raw format?

Why is it really out there? I mean, what are the odds that the Canon (or Nikon) raw format will really disappear (and Adobe won't)? It makes some sense in light (hee, hee) of Kodak's recent demise, but for the big guys?

Should I let Lightroom convert all my raw images to DNG?


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## JR (Apr 10, 2012)

I have been using dng for the past 6 months and have not seen any loss of information. One feature i like is you only have one file per picture where with canon file format there are two file for every picture. When i import the picture into lightroom, i always copy the cr2 file in a seperate directory, so i have both format anyway...

Jacques


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## Mt Spokane Photography (Apr 10, 2012)

There are three flavors of DNG.

1. Standard DNG, not lossy, smaller than CR2, you cannot convert back to a cr2 format, but can convert to tiff.

2. DNG with CR2 embeded. Not lossy, very large file, and the CR2 can be extracted, and a tiff file can be extracted.

3. Compact DNG, Lossy but better than jpg, CR2 cannot be extracted, but tiff can.

The advantage of DNG files in Lightroom, at least, is that they load much faster and do not take nearly as much time to generate the image. LR4 can take a while to generate images. The standard DNGS save disk storage space, and the compact version saves a lot of disk space. If you want to use expensive SSD storage, that might be a big benefit for now, anyway. 

There is a wide selection of editing software that can use DNG files, so you may not have to wait until raw converters are available to use your favorite software.


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## prestonpalmer (Apr 14, 2012)

I've found the time it takes to convert to DNG is not worth the effort. I just leave and use everything as CR2.

Works great. LR is plenty fast at managing 100,000 raw photos per catalog.


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## FunPhotons (Apr 14, 2012)

I convert all raws to DNG (JPG's can't be converted naturally). 

Of course there's no loss involved in converting. DNG is simply TIFF with metadata - a wrapped TIFF file if you like. There's zero reason to not convert to DNG, and a lot of good reasons to. 

I have a few cameras from different manufacturers, I really don't want a bunch of raw file formats floating around with different metadata capabilities. 

I wish all cameras would output DNG like Leica. Makes so much more sense.


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## jmp2000 (Apr 14, 2012)

I started using DNG this week due to 5DM3 purchase and I not sold yet.

A couple of comments, I had to convert 300 shots with the Adobe converter which took 15-20 minutes. Now I have double the amount of files and double the space on 3 hard drives due to backups. So at 25k shots a year, I will have to invest in more hard drives if I keep both the Raw and DNG files. Grant it drives are cheap but it's still $300-500 for two drives.

I'm on Lightroom 3 and using 5DM1 Raw files was a no brainer and quick. The bummer is LR3 will not support my RAW files unless I upgrade.

So I'll probably not use DNG in the future and I'll just upgrade to LR4 once it supports the 5DM3.


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## Aglet (Apr 14, 2012)

I don't know about all of the mfrs but Canon's CR2 file has meta data on things like the AF point(s) that was active for the shot which you can display in DPP with Com-J.

Haven't found similar feature in DNG converted from CR2.


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## jmp2000 (Apr 14, 2012)

Aglet said:


> I don't know about all of the mfrs but Canon's CR2 file has meta data on things like the AF point(s) that was active for the shot which you can display in DPP with Com-J.
> 
> Haven't found similar feature in DNG converted from CR2.



Thanks you just sold me on not using DNG!


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## CanineCandidsByL (Apr 15, 2012)

I'm more than happy to have the 10 to 30% reduction in file size. There is no loss in image quality. DNG uses a lossless compression, but otherwise the image data should be identical to the original RAW. You could get similar space savings by just compressing the RAW into an appropriate zip, rar, or other compressed file, however it would need to be decompressed to work on it. Enabling windows compression on a directory with RAW files save little or nothing.

As pointed out, in DNG some of the metadata in the original RAW file may have been thrown out. Also you wouldn't be able to insert the DNG into Canon software to have it show you that metadata or apply Canon specific algorithms. I too miss the AF points, but it doesn't have much weight against the space savings.


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## Mt Spokane Photography (Apr 15, 2012)

Although space saving is a factor (Particularly if you have a Nikon D800), the main reason is for compatibility at some future unspecified date when Canon no longer supports older models. They have already dropped much of the support for their early DSLR's that are only 8 years old, what will happen in 30 years? Promoters think that DNG will still be around.

I've played with converting mine in order to get a early read of my 5D MK III files, but so far I am sticking with cr2 plus a exported jpeg.


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