DirtFarmer Loc: Escaped from the NYC area, back to MA

Yes, it's a thread about DNG once again. No, it's not meant to push you to use it or to push you away from it. I have been hearing both side of the arguments for several years now so I decided to collect some of the arguments into one place, more for my own edification than to try to convince someone one way or the other.

I don't expect this to be the last word on the subject. I am not an expert and don't have a well-defined position on the subject yet. I looked at a lot of sites and extracted arguments for both sides and put them into a collection to share. There are a lot of sites that I did not look at, so I don't expect this to be a complete collection. It's a starting point for me.

The collection of information is at http://www.uglyhedgehog.com/user_page.jsp?upnum=1419

Note that it's pretty long. On a word processor it was 4 pages. It contains:
Posted advantages of DNG
Posted disadvantages of DNG
Some caveats and comments
My current take on DNG

Note that this is all the opinion of other people (with references included) except for the last section which is my opinion.

If anyone knows of some advantage or disadvantage that isn't found in my collection, I will be glad to add it in. However, as a farmer, I am flat out busy in the summer, which will start as soon as I can find my fields under all the snow. So I will be able to attend to this up until maybe the middle of April (based on historical average weather patterns for this area {and I should note that this has not been an average winter}). Failing that, I'll probably be free at the end of November, at which time this will probably be superceded by someone else's thread.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

I use both - and there is no practical difference in image quality between them. Some camera mfgrs are beginning to use dng as their native raw format. It is open source and not likely to go away anytime soon.

DirtFarmer Loc: Escaped from the NYC area, back to MA

Thanks for the comment. I get that there's no difference in image quality. After all, it's the same data being worked on. OpenRaw was open source too, and it went away (or at least it isn't anywhere near as prevalent as dng) so just because it's open source doesn't mean it will stick around. However, having some camera makers use it is a good indication it's likely to be here for a while.

I'd be curious to know why you use both raw and dng. I would think it would be better to use either one or the other. If the dng edits are stored in the file and the raw edits are stored in a sidecar (or in the LR catalog) it doesn't sound as if you can just switch an image between them easily while preserving your edits.

DavidPine Loc: Fredericksburg, TX

As far as I know, DNG or NEF and other raw files are just that; raw files. These files are just sensor data and "not" images. The image you see on your camera is a JPG conversion or weak process of raw data because you cannot see raw data as an image.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

The open source, Adobe's support, and how Adobe has been able to persuade Leica, Pentax and others to use dng in camera - gives it a little more of a chance of being around for a while.

When a new camera comes out and before Adobe has had a chance to reverse engineer the new raw files, their dng converter lets me continue to edit raw files.

Also, I use DXO in conjunction with Lightroom. There are some files that I will get better results by applying some of the corrections and adjustments in DXO, as they are handled better there. The process is to open the raw file in LR, Use Library>Plugin Extras>Transfer To>DXO to open the file(s) in DXO, where I edit. In DXO I then export to Lightroom which happens as a dng file.

DXO offers better lens profiles, sharpening and noise reduction, and perspective/volume deformation adjustments, and other corrections than what I can do in LR on certain images.

DirtFarmer Loc: Escaped from the NYC area, back to MA

I haven't used DXO for many years. It sounds like DXO will export a dng file. Can't you import a dng file to DXO? Or doesn't the LR>Library>Plugin Extras>Transfer To> sequence work on dng? (I haven't used that sequence so I'm not familiar with it. In fact, I don't see that menu item in the PluginExtras dropdown of my library menu {I'm using Win7 or Win8 on two different machines and to send an image to a different editor I use "right-click/edit in"}).

bull drink water Loc: pontiac mi.

my take was that it was the luck of thhe draw. you used whatever the camera was set up for. sony =arw, and pentax = dng. that's what I got so I make the most of them. I use a converter if I want to create a tiff file.

speters Loc: Grangeville/Idaho

I don't understand why there have to be sides to it, it's just a file format that some use and some not, and that to me is all there is to that. Pentax uses it for a lot of their rigs as the native format and it works just fine.

Mud2

Another related DNG question: ACR AND DPP allow major changes to the raw image before converting. Does DNG do so also?

DirtFarmer Loc: Escaped from the NYC area, back to MA

There are sides to it because people have strong opinions and are not shy about stating them. That's true of a lot of things such as whether you should shoot raw or jpg. Whether you should use a "protection filter" on your lenses. Whether you should shoot in bursts or try to carefully time your shutter release.

There are good and bad sides to dng (as well as the above examples). I just wanted to collect the pros and cons into one spot. Mainly because I wanted to decide whether to use dng myself, but I put them here because it's a source of information on the subject.

DirtFarmer Loc: Escaped from the NYC area, back to MA

Dng is just a file format. It's the editor you use that determines whether you can change the raw data before converting it into an image.

And there's a difference between changing the raw data and changing the file containing the raw data. Some have stated that dng is nondestructive because even though a new preview is written into the dng file (thereby changing the file), it's a nondestructive process because the raw data contained in the file are not changed. <my opinion> I do not agree with this point of view. If the file is changed in any way, it is not a nondestructive process. You have to rewrite the whole file, even if a portion of it is not changed. </my opinion>

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

This only works with DXO 10 - it definitely exports a DNG to LR. DXO will not read a DNG file, even if it is the one it exported it to LR.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

The process is linear - when I transfer an image to DXO, it is the original untouched raw file from the camera, it does not read any of the edits you might have made in LR before transferring. You make the edits you need to make in DXO, then the image is exported to LR to continue editing, or to use the "edit in" command to open a PSD or TIF copy in PS, OnOne, etc etc - for image finishing. It takes longer to type this description than it does to actually do it - at least on a fast computer.

romanticf16 Loc: Commerce Twp, MI

You can convert your camera's RAW file format to DNG, and still save the original RAW files. The only reason for doing this would be if you wanted to use the manufacturer's software to PP the digital files. Nikon software won't work with DNG, only with NEF files. I'm sure Canon doesn't work with DNG files with their software either.