I have used Adobe DNG Convert to replace my Nikon NEF Raw files with Adobe DNG files prior to entry into Lightroom. I have chosen to use this route.
I have set the preferences as follows .. Using Raw 7.1 or greater ... JPEG Preview: Medium size...Embed fast load .. Don't use Lossy Compression...Preserve Pixel count ... Don't embed originals. OK! All conversion went smoothly ... over 10,000 photos converted.
Now my question is: When I look at the photos using Windows 10 Photo Viewer ... the DNG photos are significantly reduced in quality compared to looking at the corresponding original NEF photo with Windows Photo Viewer. My concern is this ... when I look at the DNG photo with Windows Photo Viewer, am Iooking at the Medium size JPEG Preview and is that why the photo is much poorer in quality? My concern is that when I import into Lightroom I want to be working with the best quality photo. I have saved all my original NEF files so if necessary I can do away with the DNG files and replace quickly with the originals In my reading, I was under the impression that using DNG files would be easier in that the XMP files are stored internal to the DNG files and I do not have to keep track of them and that seemed easier for me. Also I understood that the quality of the DNG file would be the same as the quality of the original Raw NEF file.
I am totally new to photo manipulation and have not yet imported anything into Lightroom. I have been trying to organize all my photos ..many photos ... 25,000 plus .. many of my photos are not RAW photos taken before I had my Nikon D300. My reading highly recommends careful and consistent file organization prior to entry into Lightroom and I have spent several weeks coming up with a meaningful schema for organizing my photos. And in my last step I was going to convert NEF RAW files to DNG to save room and to save organization issues later (ie...not worrying about XMP files).
So I am questioning why when I look at the DNG photos and compare to the NEF photos using Windows Photo Viewer, why are the DNG photos of much poor quality than the NEF photos?
I'm wondering why you are converting to DNG if Lightroom can open the original NEF files. There isn't that much of a space savings with NEF files. At least that is my experience with my D7100. I only see about a 15% decrease in file size. But there's nothing wrong with DNG files if that is the way you really want to go. Unless you have told Lightroom specifically to save changes to XMP, there are no XMP files when using Lightroom. All changes are stored in the catalog. I occasionally convert to DNG primarily to experiment. I have never experienced a decrease in quality in the previews. But remember that when you are editing using Lightroom the JPEG preview is only used to momentarily until a preview of the raw data can be created.
I have read the advantages and disadvantages of using DNG files ...and yes on using Adobe DNG convert I do not save enough space to real justify the conversion.
I simply am a total novice at this and I am not finding a really good explanation on how to use Lightroom. My concern was to assure that changes made in Lightroom would be preserved in case the Lightroom catalog is corrupted somehow. It seemed to me my reading indicated that XMP side car files was a back up way to insure the photo changes are still available in case the catalog is damaged.
Any suggestion in this regard?
If I store my original files on an external hard drive ... should I store the catalog there also so I have trans-portability of my photos. This lightroom stuff is a bit confusing. Also I had read somewhere that an XMP side car file is stored inside of JPEG files and TIFF files. So I was partially converting to DNG so that storing of XMP files would be consistent across all my photos. I have many photos that are JPEG or TIFF that were taken before I started using RAW or NEF files.
I do thank you for taking the time to address my original question. Yes I am considering not using DNG but still confused. Perhaps that is just me.
It seemed to me my reading indicated that XMP side car files was a back up way to insure the photo changes are still available in case the catalog is damaged.
I do not use DNG. If you use DNG and chose to save the XMP data to the file as a backup it is saved INSIDE the DNG, not as a sidecar file so your DNG is getting written to all the time. If you use NEF than the data is written to a sidecar XMP and the original NEF is never changed. I prefer my RAW files to be left alone.
Changes are stored in the file header for DNG, JPEG and TIF files. But really, if you make a conscious effort to always backup your catalog and save the catalog to a different hard drive than the working catalog, you should feel confident. Additionally, you need to make sure that you have some sort of backup routine to back up your images because Lightroom doesn't do that. And those backup images should also be stored on a separate hard drive.
Here's another good resource for learning Lightroom. If you are confused about how Lightroom works you will do yourself a big favor if you will stop and watch a few tutorials and read the other resources that have been provided for you. Once you get the basic concept of Lightroom embedded in your head you will find it very easy to work with.
Quote "So I am questioning why when I look at the DNG photos and compare to the NEF photos using Windows Photo Viewer, why are the DNG photos of much poor quality than the NEF photos?"
Simple Windows Photo Viewer is a file browser and does not have the ability to process the raw file data, so it displays the thumbnail which you see on your camera screen and imbedded in the file header.
Lightroom builds its own previews when importing the DNG files. i.e Lightroom has the processing ability to render a viewable image from the raw data.
I thank you for responding to my question.
If possible ....do you have a recommendation of a book or a web site to give a comprehensive explanation of how to begin and to use Lightroom?
Again thank you,