I want the best of both worlds – I want smaller file sizes, no sidecars and updated previews on my working drive so I use DNG for my main working files, but maybe one day I might want a proprietary raw file for something, so I keep one of my offline backups as a proprietary raw format.  I want the files to have matching names and folder structure, so converting on import doesn’t work for me, so this is my current workflow:

1. Import with backup turned on – this is a temporary backup, just in case something goes wrong before I finish sorting.
2. Rename files – the proprietary raw files now have the new names
3. Use the OS or File Sync software to copy the images to my offline backup structure.  Export as Original format to the other drive would do the same.  That drive is then disconnected again.
4. Select all in Grid view and go to Library menu > Convert Photo to DNG with ‘delete originals after successful comversion’ turned on swaps my proprietary raw files in the catalog for new DNG files, and removes the proprietary files from the hard drive.
5. That leaves me with DNG files in the catalog, complete with all of the settings that were previously attached to the proprietary raw files.  The proprietary files are safely backed up on my offline drive, with matching file names and a matching folder structure, just in case I ever need one.  Ok, I’ll admit, I’ve never been back to them yet, but you never know! 

Every time I hear someone say ‘I deleted the photos because I thought Lightroom backed them up’, my heart sinks.

I can’t say this loudly enough – back up your photos as well as letting Lightroom back up its catalog.  Lightroom doesn’t do that for you.

Ok, by default, the catalogs are backed up in a ‘backups’ subfolder alongside the original catalog.    If you don’t regularly back up that whole drive to a second drive, what will happen when your main drive dies?  You’ll have dutifully run Lightroom’s backups – and they’ll be on that dead drive along with the original catalog.  That’s not much help!

So what are you going to do?  You really need to have a backup system that very regularly backs up your entire hard drive contents to another hard drive (not just another partition) AND you still need to run Lightroom’s backups.  Lightroom’s backups are a safety net against catalog corruption, and the hard drive backup protects against hard drive failure.  You definitely want both.

If you haven’t got that set up, at least in the meantime set Lightroom’s backup to back up the catalog to another drive, otherwise all your hard work could be gone with that nasty click click click of a dying drive.

So how do you change the backup location?  Here’s the instructions from Adobe Lightroom 2 – The Missing FAQ:

How do I change the backup location?

The backup directory is changed in the Back Up Catalog dialog, which appears when a backup is due to run.

If you need to show the Back Up Catalog dialog to change the location when a backup is not normally due, you can run a backup on demand.  To do so, go to Catalog Settings > General panel and change the backup frequency temporarily to ‘when Lightroom starts’.  Restart Lightroom so that the backup dialog comes up, and then you’ll be able to change the backup location.

Don’t forget to then change it back to your normal backup schedule.

For those of you who aren’t NAPP members, you’ll want to sign up now!!!

In the meantime, here’s the main bullets points directly from Adobe Lightroom 2 – The Missing FAQ

File size
DNG files are generally 10-40% smaller than their original proprietary format, depending partly on the size of the preview that you choose to embed.

XMP Sidecars
Proprietary raw formats have their XMP data stored as a sidecar XMP file, whereas DNG files have that information embedded within the single DNG file.  The question is, do you find sidecar files a pro or con?

Long Term Storage
The DNG format is openly documented, which means that it should be supported indefinitely, whereas proprietary formats such as CR2, NEF, RAF etc. are not openly documented.  Will you be able to find a raw converter in 20 years time that will convert a proprietary format when that camera model is ancient history?

Manufacturer’s Software
Most manufacturer’s own software will not read a DNG file, only their own proprietary formats.  Do you ever need to open a file in the manufacturer’s own software?  If so, you’d want to embed the proprietary raw file – it can be extracted use the DNG Converter tool, however it does negate the file size benefits.

MakerNotes
While there is DNG support for MakerNotes, some manufacturers don’t stick to the rules, and therefore MakerNotes embedded in an undocumented format can’t always be carried over to the DNG file, however if you’re not sure what the MakerNotes are, you probably won’t miss them.

Check the Photoshop User article for lots more pros, cons and how to’s.

However let’s exercise a little more caution… you wouldn’t want to risk damaging your last backup, so first, you’ll want to duplicate it and put it back in the right place.

Let’s assume your main catalog is stored at My Documents\My Pictures\Lightroom\Lightroom 2 Catalog.lrcat, and your existing catalog has somehow become corrupted, or you’ve deleted photos accidentally.

By default your backups would be stored at My Documents\My Pictures\Lightroom\Backups\dated folders\Lightroom 2 Catalog.lrcat.

First rename that main catalog, rather than deleting it, just in case you want to go back to it.  We’ll call it ‘Old Catalog.lrcat’ for the moment.

Now go into your last dated backup folder and select the Lightroom 2 Catalog.lrcat file (or whatever your catalog is called).  Copy it (Ctrl-C for Windows, Cmd-C for Mac) and go back to your main catalog folder where your catalog usually lives.  Paste your copy of the backup catalog (Ctrl-V for Windows, Cmd-V for Mac) into that main catalog folder.  Doing that copy/paste has left your backup catalog exactly where it was, but created a copy in the normal location.

Double click on that catalog to open in Lightroom.  If it works correctly, you can now delete ‘Old Catalog.lrcat’, and carry on working.

Hopefully you already have a sensible backup facility in place, but unless your backup system keeps different versions of each file, it’s still worth letting Lightroom’s integral backup run too.  Why?  Because otherwise you could end up accidentally overwriting a good copy of your catalog with a corrupted copy.  If you let Lightroom’s backup run too, then you’ll have uncorrupted copies of your catalog too.

Lightroom’s integral backup simply takes a copy of your catalog and places it in dated subfolder.  We’ll cover how to change the backup location, and how to restore backups, in future posts.

Don’t forget, Lightroom’s backup does NOT back up the photos.  You need to do that yourself.  My personal preference is for File Synchronization software – Vice Versa for Windows or Chronosync for Mac are my favourite.

The white balance is perfect on photo A, so you sync the settings to photo B… but it doesn’t change.  So you try it again… and it still doesn’t change.  Why?

As Shot is the key.  If photo A is set to As Shot white balance, photo B will also be set to As Shot, not the same numerical values.

To solve it, select ‘Custom’ from the white balance dropdown, or shift the values slightly, and THEN sync with photo B, and your numerical values will then be copied.

Lightroom uses the profile differently to other programs (perceptual rendering rather than relative colorimetric), so corruption in that part of the profile shows up even though it is not noticeable in other programs.  It often happens with the canned profiles that come with many monitors.

Ideally you should recalibrate your monitor with a proper hardware calibration tool, however not everyone has one to hand.  To confirm that the profile is the problem, you can remove it and replace it with a standard profile.

How do I change my monitor profile to check whether it’s corrupted?

Windows XP

1. Exit Photoshop Lightroom.
2. Choose Start > Control Panel > Display.
3. Click the Settings tab.
4. Click the Advanced button.
5. Click the Color Management tab.
6. Click the “ADD…” button.
7. Choose a standard RGB color profile, (i.e. sRGB IEC61966 – 2.1. )
8. In the “Color profiles currently associated with this device” field, select the new profile you just picked.
9. Click the “Set As Default” button.
10. (Optional) Select the old profile.
11. (Optional) Click the Remove button.
12. Click the “OK” button.

Windows Vista

1. Exit Photoshop Lightroom.
2. Choose Start > Control Panel > Color Management.
3. In the “Profiles associated with this device” field, select the default monitor profile.
4. Click the Advanced tab.
5. Click the Remove button. or Change the Device Profile to a standard RGB color profile, such as sRGB IEC61966 – 2.1.

Mac OS X

1. Go to System Preferences > Display
2. Select the Color tab
3. Press the Calibrate… button and follow the instructions.  Turn on the Expert Options and calibrate to gamma 2.2.

Excerpt from Adobe Lightroom 2 – The Missing FAQ

There are a number of options to choose from when importing your photos, and which you choose will depend on your own browsing habits.

Minimal shows the thumbnail preview embedded in the file.  It’s the quickest option initially, but it’s a very small low quality preview (i.e. usually with a black edging and about 160 px along the long edge) so you then have to wait to render previews as you browse.  Minimal previews are not color managed.

Embedded & Sidecar checks the files and their sidecar files for larger previews (approx. 1024 px or larger), giving you the largest ready-built preview it can.  It’s still just a temporary option – Lightroom will build its own previews as soon as it can.

Standard builds a standard-sized preview used for browsing through the photos.  You set the size and quality of these previews in Catalog Settings.  Standard-sized previews are highly recommended – it will greatly speed up browsing performance if Lightroom isn’t having to render previews on the fly.

1:1 previews are full resolution so they take up more space, but if you wish to zoom in on your photos in Library module, it will save Lightroom having to render 1:1 previews on the fly, which would slow your browsing experience.  If you’re concerned about the disc space that they take up, you can set them to delete after a fixed time (in Catalog Settings), or you can discard 1:1 previews on demand by selecting the photos and choosing Library menu > Previews > Discard 1:1 Previews.

You can either choose to render either Standard-Sized or 1:1 previews in the Import dialog or if you wish to render the previews later, select all (or none) of the photos in Grid view and choose Library menu > Previews > Render Standard-Sized Previews or 1:1 Previews.

In early version 1 releases, rendering previews at the same time as importing was much quicker than rendering them later, but this difference is no longer noticeable.

This release adds the same improvements as before, but solves 3 major bugs that were introduced in 1.4.

Quoting Tom Hogarty on the Lightroom Journal:

Lightroom 1.4 incorrectly modified the EXIF time date field of images that had a metadata update applied. This incorrect modification does not appear in Lightroom or Bridge and is only viewable through third party EXIF tools. This error has been corrected in Lightroom 1.4.1 and all files in a Lightroom catalog that have been incorrectly modified will be corrected on their next metadata update. (Metadata can be updated by selecting the files in the Library grid view and choosing Command or CTRL + S to save and update the metadata.)

Olympus JPEG files could render incorrectly in Lightroom 1.4, displaying an artifact in the exported file.

Any conversion to DNG in Lightroom 1.4 (Windows Only) would cause the DNG file to become unreadable by Lightroom’s Develop Module or Camera Raw 4.4 in Photoshop. The issue has been corrected and files can be converted to DNG again in order to resolve the issue for existing files. Returning to the original native raw files is not necessary. The affected DNG files can be selected and converted again using the DNG Converter 4.4.1 available at www.adobe.com/dng/. This process is not required but recommended to ensure that a correct validation value is stored within the DNG files.

Lightroom 1.4 provided degraded import performance relative to Lightroom 1.3.

Those bugs are fixed in 1.4.1.