This is confusing stuff and you are on the right track. Metadata is any textual information added to a digital image.

By converting to the Dng file format this textual information– your copyright for example–can be stored along with the raw sensor data inside of each file. Raw files in proprietary, meaning camera brand specific, formats cannot hold this sort of text internally. Since they can’t store the info internally these files need a sidecar xmp file, think of it as a post-it note, to hold important information.

This internal vs. external metadata storage is a property of the file’s themselves regardless of what image management software you use. What makes Lightroom special is that it builds a searchable index for your photography.

For every file– meaning every photo–that is added into your index Lightroom creates an “index card.” Each “index card” records the file’s name, it’s location on your hard drive, all of it’s metadata, and a couple of thumbnail-sized copies of the image.

Searches in Lightroom produce almost instantaneous results because the catalog keeps its own records about your images. (See Lightroom vs. Adobe Bridge for more details.) Not only does the catalog produce instant search results but it can also store information that is not part of the file’s metadata. Features like the pick / reject flags, collections, and virtual copies are all stored only at the catalog level. There in’t a metadata field for the name of a collection or for a virtual copy.

What I am trying to say is that we need the catalog for two reasons: a, fast searches even if the file’s themselves are offline and b: to store features of the program that cannot be written into a file’s metadata.

I hope this helps,

David

what i understand here is Catalog= metadata, DNG= metadata+photo. so if we have both metadata and photo in DNG file, why we need Catalog to record the metadata? sorry to confused u :d

I am not sure that I understand your question. This tutorial is all about how to shift your raw files into the dng format within Lightroom. You would only use the “Import as Catalog” feature if you were combining one catalog into another. Why and where are you using this option in your routine?

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David

Grant Gunderson, one of my favorite photo editors / publisher, is now accepting “Dng raw files” with “meaningful metadata” only for consideration in his magazine The Ski Journal. I believe that we will soon see similar rules from all of the topflight publishers. Click here to see The Ski Journal’s complete submission guidelines.

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David Marx

I prefer DNG anyway, but I know it’s frustrating when things don’t work the way they should.

-Scott

Thanks,

Andrew

Thanks for you comment. As a teacher, I keep a lot of my mistakes, as well. However, I see students time and again who have unmanageable catalogs due to the sheer volume of mediocre images. One of the most frequent mistakes made by amateurs when showing their work is that they flip through image after image of bad shots muttering the mantra “Ok, there’s a good one coming up here somewhere…”

Anyone who’s sat through a slideshow of someone’s vacation pics can attest to that!

@Andrew:

I’ve not run into that issue before. Were you importing straight from the camera or were you using a card reader? Although an import with the camera plugged directly into the computer should work, I always recommend using a memory card reader. They are typically much faster and can reduce the (already low) likelihood of damage to your camera from a USB power issue.

-Scott

This morning, before calling Apple again(!) I tried converting to DNG on import and bingo, no problem. Has anybody else experienced this problem on a Mac with NEF files? I think I’ll stick to DNG in the meantime though!

I have read of photographers having another catalog that is just their best takes. That may be a good option so you don’t have the outtakes cluttering up the final picks in a catalog.

I do of course edit out the really bad, totally blurred, over/under exposed, etc.

That’s my 2 cents.

Yes, as long as the Automatically Write Changes to XMP checkbox is checked (or you save changes to your files), the metadata is written to the DNG file. No more sidecar files.

For me, it’s certainly the best solution.

-Scott

-Scott

PS-I’m not that great at it yet. I could use some work on narrowing down my library!