Downsides of CR2>DNG conversion?

I've heard Lightroom can operate more efficiently with DNG vs the proprietary CR2 files. The #1 thing I've heard is that you may lose some of the proprietary data that could be used later on.

So I guess, basically:
1) Any other downsides to converting to DNG?
2) Has there been any instance, so far, where the converted DNG lost information that (for example) an updated version of LR was able to use from the CR2 file? Or is this just a fear of something that may never be?

I think you heard wrong. If LR can work with your CR2, it can work with your CR2. In order to make a DNG, Adobe first has to work with the CR2, in order to make a DNG. Tautology defined. If Adobe can work with your CR2 to produce a DNG, it can work with your CR2, period. Cut the middle man and work with the CR2 directly.

The DNG can either contain, or not contain, the original CR2. If you are saving the CR2 in the DNG, why bother with the DNG? If you are NOT saving the CR2 in the DNG, are you saving it separately? If you are saving the CR2 separately, or saving it in the DNG, you are doubling your storage needs. Some people tout the 'permanence' of DNG as a virtue. Bull-puckey. If DNG Converter can open your raw file now, it will be able to open your raw file 20 years from now, when other programs can't. Convert you raw to DNG then.

Adobe's original hope was that all camera manufacturers would adopt the DNG as THE raw format for digital images. Had that happened, DNG would be ubiquitous. That did not happen. So, in order to keep itself relevant, Adobe has continued to add support for each new camera.

The only purpose DNG serves is so programs like LR5 can open your XXD files. Adobe will continue to add support for new cameras. Sometimes with updates, sometimes with new versions. As such, DNG serves no real purpose.

Tell us what you really think.

Speed of backup is the BIG downside. Especially in these days of cloud backups.
https://www.damiensymo​nds.net …to-dng-or-not-to-dng.html

joemusic321 wrote in post #18446847
Tell us what you really think.

Ok. The most data you can ever have is in the raw file. Converting it to DNG does not add color, clarity, saturation or focus. It can't improve your composition, lighting or focal length choice. DNG serves no purpose. Your raw file is the best it gets. Why do you think Adobe incorporated the ability to store the raw file inside the DNG?

Bassat wrote in post #18446869
Ok. The most data you can ever have is in the raw file. Converting it to DNG does not add color, clarity, saturation or focus. It can't improve your composition, lighting or focal length choice. DNG serves no purpose. Your raw file is the best it gets. Why do you think Adobe incorporated the ability to store the raw file inside the DNG?

What I wonder is things that are beyond the "sensor" data, and ultimately whether those things are useful or not.

Obviously we're able to access the focus point because I have a plugin that shows me. Does the DNG still keep that? What about focus mode? I just wonder if there are things in the current CR2 file, or maybe a future one, that would be "lost" if converted to DNG. Maybe there isn't anything, or maybe what's there is ultimately so minimal and worthless.

The reason I spoke about conversion to DNG wasn't because "it's the future", but because I had heard LR handles it more efficiently, ultimately making LR faster. Maybe some truth to that, maybe none...

kaitlyn2004 wrote in post #18446882
What I wonder is things that are beyond the "sensor" data, and ultimately whether those things are useful or not.

Obviously we're able to access the focus point because I have a plugin that shows me. Does the DNG still keep that? What about focus mode? I just wonder if there are things in the current CR2 file, or maybe a future one, that would be "lost" if converted to DNG. Maybe there isn't anything, or maybe what's there is ultimately so minimal and worthless.

The reason I spoke about conversion to DNG wasn't because "it's the future", but because I had heard LR handles it more efficiently, ultimately making LR faster. Maybe some truth to that, maybe none...

1.) You will never have more data than what your raw file contains. DNG can't help that.
2.) Adobe (LR) HAS TO handle your raw file to create a DNG.
3.) If Adobe ever decides to make LR work noticeably better with DNG than with camera raws, people will NOT convert everything to DNG. They will abandon Adobe/LR.

When I bought my 80D, LR5 could not work with the raw files. I automated the conversion to DNG process (link to my process: https://photography-on-the.net …/showthread.php​?t=1472058). It was still a major pain in the Kiester. I upgraded my LR to version 6, which handles my 80D raw files just fine.

+10 to Tom's comments. There is only one valid reason to convert to DNG and that is if you have an older version of LR (3, 4 or 5) which does not support your new camera's native RAW files.

The claims that DNG format is future proof are just that, claims. It is just as likely that DNG format will one day fall by the wayside as it is that a native RAW format will. If, at some point in the future you find that editing software companies start to abandon a RAW format that is the time to convert to whichever new format is best.

Dan Marchant wrote in post #18446968
+10 to Tom's comments. There is only one valid reason to convert to DNG and that is if you have an older version of LR (3, 4 or 5) which does not support your new camera's native RAW files.

The claims that DNG format is future proof are just that, claims. It is just as likely that DNG format will one day fall by the wayside as it is that a native RAW format will. If, at some point in the future you find that editing software companies start to abandon a RAW format that is the time to convert to whichever new format is best.

Dan I do have three other reasons to create DNG files. The first is when I shoot using Magic Lantern's DualISO feature in my 50D. This requires that the CR2 file is pre-processed to equalise the alternating ISO row pairs. The pre-processing software creates a new DNG file for final conversion.

The other two reasons are when I use the RAW Panorama and the RAW HDR features, both of which also create new DNG RAW files for conversion. Personally I have had very good results using the RAW Panorama stitching option, but mixed results with the HDR. I have shot a couple of three shot HDR's that are also part of a pano, they have made a nice series of HDR DNG's to then stitch into a combined Pano-HDR DNG file. While I have had really poor results from doing -2 to +2 @ 1/3 stops for 13 image HDR's of a sunset. They seem to end up with bad banding in the sky. I have to say that MS ICE also seems to have issues with them.

Alan

The only CR2 files I convert to DNG are those taken with my IR converted 7D. Since I use Lightroom in processing, I had to set up a custom camera profile using Adobe's DNG Profile Editor in order to overcome Lightroom's white balance limitation when working with raw IR..

The reference to "Lightroom can operate more efficiently with DNG vs the proprietary CR2 files," in the OP, apparently refers to the option during conversion to DNG to embed "Fast Load Data". The first time you open a Raw image file in the Develop module LR/ACR does a partial default conversion to a preview display image and stores it in the CR Cache folder. This facilitates quicker loading/displaying of subsequent openings of the Raw. However, depending on the CR Cache size you have set in Preferences and factors like the numbers of files you are opening, the time span, and the drive on which the Cache is located, if the stored data for that particular Raw has meanwhile been removed to make room for data from other Raws, it will have to be recreated. Thus, in some cases the CR Cache can become a bottle neck. The DNG with Fast Load Data eliminates the need for LR to reference and write to or read from the Cache folder because the same data is already in the file metadata.

I'm surprised no one has mentioned the major downside of DNG; that DPP doesn't support it. DPP is "free" (or a coerced purchase included in the camera's cost, depending on your point of view) and reasonably good as long as you are not pushing its limits. I rarely use it, but it can provide an interesting or informative alternate conversion.

tzalman wrote in post #18447112
I'm surprised no one has mentioned the major downside of DNG; that DPP doesn't support it. DPP is "free" (or a coerced purchase included in the camera's cost, depending on your point of view) and reasonably good as long as you are not pushing its limits. I rarely use it, but it can provide an interesting or informative alternate conversion.

Elie I don't know what it is like now, but I remember that in the early(ish) days of DNG, when Adobe had got some manufacturers to support DNG in camera, that a lot of the third party software that supported DNG could only work with camera produced files. A pretty big limitation that Adobe conveniently forgot about in their bids to push DNG, since they were saying look at how many programs support DNG, this is why you should convert your images to DNG.

I also notice that DNG still has issues with versioning when doing conversions for new cameras, as you have to pick the right version of DNG to match the version of ACR/Lr that you want to convert for. So again it seems that DNG may not be as universal as Adobe would like.

Alan