Converting to DNG: What are we losing?

[digitaldog]

<blockquote>

<p>Anyone else remember Adobe dropping the .jpg2000 format?</p>

</blockquote>

<p>Nope, because they just didn't install, by default the JPEG2000 plug-in, you have to do it. Or download another of your choice. The original works just fine in my copy of CS6 and this one does as well:<br>

http://www.fnordware.com/j2k/</p>

<blockquote>

<p>As just pointed out, <strong>you bake in your edits</strong> with dng<br /></p>

</blockquote>

<p>In the raw/DNG? <strong>No you don't.</strong> You're making either XMP metadata instructions or you're saving a rendered JPEG of considerable size of the current rendering within the DNG (along with other useful data). The raw data is still raw. READ the articles by Peter Krogh from the ASMP! <br>

Get the facts straight, enough made up stuff please. </p>

[digitaldog]

<p>In the other real world, even Save for Web supports JPEG 2000 within CS6:<br>

<img src="http://digitaldog.net/files/jp2.jpg" alt="" /></p>

[EricM]

<p>"Made up stuff", that's funny after dodging direct questions. Here's more, where do you get this stuff?</p>

<p><strong>"IF you are NOT using the Nikon converter, you're not missing nor need this metadata one bit (literally)."</strong><br>

<br>

More (made up) biased opinions yet wrapped up as a fact. Perhaps it's best to tell us what is in this info that is being discarded and people can make up there own minds. There is all sorts of camera model-specific info and data used for lens corrections etc that gets discarded.</p>

[digitaldog]

<blockquote>

<p>There is all sorts of camera model-specific info and data used for lens corrections etc that gets discarded.</p>

</blockquote>

<p>OK, and just what raw processor(s) can use it? The answer has been correctly stated several times now. Again, proprietary info, only one converter can use can't be used by any other converter. More so, even though it is proprietary, it can still be embedded into the DNG. <br /> For the last time, the degree of rawness of a converted NEF or CRW is <strong>exactly as raw</strong> as it was before the conversion. Understood?<br>

Made up stuff? Like your continuing incorrect statement about JPEG 2000 and Adobe, made up or just pure ignorance. </p>

[digitaldog]

<blockquote>

<p>Here's more, where do you get this stuff?</p>

</blockquote>

<p>I read up on the subjects, written by experts in the industry who support peer review. You should try it some time. You might be less inclined to write things that are completely incorrect and untrue. I've provided several links, just three today from the ASMP. You have a beef with what they wrote? I suppose we can be kind and call you a peer, so please, peer review the text and as I know Peter well, I'll pass along the corrections to him so the ASMP can review your findings. <br>

<br>

You've made up a number of metrics about the market with zero reference. You were dead wrong about JPEG 2000. You seem to still misunderstand the effect on raw data before and after conversion to DNG despite my attempt to explain it to you several times. Other poster's have said the same things about proprietary metadata. <br>

<br>

You're not to be taken seriously based on your track record here! </p>

[EricM]

<p><strong>"OK, and just what raw processor(s) can use it? The answer has been correctly stated several times now. Again, proprietary info, only one converter can use can't be used by any other converter."</strong><br>

<strong> </strong><br>

I understand Dx0 uses it. As well as Nx2 of course. <br>

<br>

<strong>"For the last time, the degree of rawness of a converted NEF or CRW is exactly as raw as it was before the conversion. Understood?"</strong><br>

<br>

I understand alright. That you wont answer direct questions that gets to the truth of the matter. I'm glad to be re-assured that when using nef/xmp files, I wont have the same dng problem of “baking in” some of the changes and in which decreases my flexibility to re-edit.</p>

[digitaldog]

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<p>I understand Dx0 uses it</p>

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<p>You understand or you know? If it's proprietary, Dx0 can't understand it. If it isn't proprietary, most converters which have the capabilities to use it will use it if they find it useful. LR/ACR didn't originally have any lens correction. So whatever was written, proprietary or open metadata (like the lens type, aperture) was seen. LR/ACR got lens correction. EVEN if the lens data isn’t' proprietary, it might not use it. It's a totally different technology. <br>

IF you understand what the term proprietary (in this case metadata) means, then you should have zero problems understanding what is and isn't lost. And even if this NEF metadata is gone, you're using a different converter which may do a much better job at lens correction among other features. </p>

<blockquote>

<p>That you wont answer direct questions that gets to the truth of the matter.<br /></p>

</blockquote>

<p>You should start trying to answer questions, as thus far you're way, way behind. </p>

<blockquote>

<p>I'm glad to be re-assured that when using nef/xmp files, I wont have the same dng problem of “baking in” some of the changes and in which decreases my flexibility to re-edit.</p>

</blockquote>

<p>That was never an issue from day one although for some reason, you found it necessary to take us all down that rabbit hole. </p>

[EricM]

<p>It's a simple yes or no. If I never used dng, and instead used nef and xmp from day one (in Adobe products), I wouldn't have the dng problem of <strong><em>“baking in” some of the changes to the raw file, which does remove some flexibility to re-edit your files"?</em></strong></p>

<p>Rabbit holes. Like this one?<br>

http://www.photo.net/digital-darkroom-forum/00bCAi</p>

<p>Have a good day.</p>

[pete_s.]

<p>Just for the fun of it I ran some D600 files through the latest DNG converter 7.2 from Adobe.</p>

<p>D600 and all Nikons AFAIK embeds two jpeg images into their raw files, one low resolution preview and one full resolution jpeg.</p>

<p>If you setup the DNG converter to JPEG Preview: Full Size the size of the DNG is a few hundreds KB larger than the original raw file. So <strong>when the DNG files are smaller it's just because the embedded JPEG is smaller</strong>. Otherwise DNG files are roughly the same size.</p>

<p>What I did find however was that the DNG converter actually does a raw conversion to make a preview image instead of taking the one the camera put in the raw file. The DNG converter by default also makes a very saturated preview image so it doesn't look like the original in the camera.</p>

<p>The EXIF info in the DNG seems to be identical to the EXIF in the raw file, except that I couldn't find the user comment field in the DNG. That is a information field, for instance a copyright notice, that you can enter in the camera and it will end up in raw files and jpeg images.</p>

<p>One use I found for DNG while playing with this is to take full resolution raw and turn them into lower resolution raw. That could be valuable for instance for D800 users that want a fast raw workflow but doesn't really need all 36 megapixels for 99% of the shots. For instance wedding shooters, where the bulk of the images never will be used bigger than for 8x10s (about 8 megapixels required).</p>

<p> </p>

[digitaldog]

<blockquote>

<p>D600 and all Nikons AFAIK embeds two jpeg images into their raw files, one low resolution preview and one full resolution jpeg.</p>

</blockquote>

<p>I don't believe that's the case with Canon raws. I believe there is only a small JPEG that matches what was shown on the LCD of the camera. As LR imports this (either raw or DNG), it shows for a second, then it is updated since ACR/LR have to replace it with it's own rendering of a preview. IOW, that initial preview from the embedded JPEG isn't useful and gets replaced. This causes a lot of questions on the UtoU forums as people think something is wrong and want the original preview back. But except for the manufacturer's converter, all other raw converters <strong>have</strong> to build their own preview using their own engines. </p>

<blockquote>

<p>If you setup the DNG converter to JPEG Preview: Full Size the size of the DNG is a few hundreds KB larger than the original raw file.</p>

</blockquote>

<p>In this case, the current rendering of the raw converter is what is built. You can update this at any time (in LR, you have to use the update DNG metadata and preview command). Even if Auto Update XMP is on, you do not get an updated preview without using this command. Which makes sense, you would not want to have LR update the JPEG automatically. </p>

<blockquote>

<p>What I did find however was that the DNG converter actually does a raw conversion to make a preview image instead of taking the one the camera put in the raw file.</p>

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<p>Correct, it has to for the reasons I outlined above. This would be true if you didn't have a DNG, the preview has to be created (and you can control the size in preferences) as the original preview isn't correct, it was built by the camera from the raw. Instead of the preview being embedded in the DNG, it's part of the LR database. Note too there are more than one preview in LR (one set is used in all modules expect Develop, the other is partially rendered and is either the ACR cache OR the DNG Fast Load data). </p>

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<p>For instance wedding shooters, where the bulk of the images never will be used bigger than for 8x10s (about 8 megapixels required).<br /></p>

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<p>The other option would be lossy DNG. The two are quite different. One is the full rez but partially processed (Lossy), the option you speak of I believe is still fully raw but smaller? </p>