Adobe Lightroom / Discuss

ambient troutmask says:

Before Posting a question read this


The Adobe Community Help system is a great source of answers to most questions posted here. Many of the links and answers in this FAQ are now to be found directly within the help system. Just click F1 when LR is running and search for what you want. I would guess that 9 out of 10 questions posted here are answered in the Help system...so please use it before posting.


The Very Basics of How Lightroom Works

You take a photograph and transfer it to your computer, it is stored in a folder somewhere on your hard disk. Within that photograph file is stored some meta-data about the photograph (the EXIF data) including f-stop, shutter speed etc etc.



When you import a file into LR you are essentially telling LR about a file on disk. It looks at the file, reads the metadata and creates a record within it's own database (called a LR catalog) and stores what it knows about the photograph in that record. What is key to understand LR is that at all times the original photo remains unchanged, it stays in it's original state regardless of what you do in LR. LR creates a JPEG 'preview' of the photo, stores it against the record in it's database and that's what it displays when you are in library mode.



If you edit the photograph LR takes the original photo, applies the effect of the changes you've made and displays what the photo looks like with these changes applied. It does NOT change the original photo data. It keeps a note of these changes in it's database, against the record it created for the picture when you imported it.



If we assume we've taken a photograph and used LR to increase the exposure by 1 stop then LR has a record for that photo and against that record are the instructions to 'increase exposure by 1 stop'. When you view the photo from within lightroom that instruction is applied to the original data and you see a lighter file. Again be clear - the original photo data remains the same. If you use some other piece of software to 'look' at the photo on disk you will see it as you took it, no changes applied.



If you now want to do something with your 'new' photo, lets say post if on Flickr, you have to export it, with the LR changes applied and thus create a new file. You now have 2 copies of the same photo, one the original and one the version with changes applied. Having done whatever you needed to with the 'new' file (lets assume uploaded to Flickr) you can delete it, safe in the knowledge you can create another identical copy from within LR should you need it (assuming you do no further edits to it with LR).



If we understand the above then hopefully we can see that in order to have an adequate backup of our body of work we need to ensure two things are safe:



1) The original photo file

2) The LR catalog where all out work (edits to be applied) are stored.



LR offers a method of backing up it's catalog automatically (not the image files, the catalog). What's important is the user ensures that copies of the backup-up catalog are stored somewhere other than the same disk of the same computer. If you lose the hard disk and all your backups are on it you lose the lot.



That's the basic position, it gets a whole lot more complicated once to start to consider virtual copies, metadata sidecar files etc

The Top Ten "Gotchas" (Now Twelve)
© Victoria Brampton "The Lightroom Queen"

1 Lightroom is all about non-destructive editing – so don’t try to save over your originals.

2 Lightroom doesn’t ‘contain’ files, it just holds data about them – so don’t go deleting your originals thinking that they’re safely stored in Lightroom.

3 Lightroom’s backups don’t back up your originals – you still need to do that.

4 Lightroom’s catalog is just a database, and databases can become corrupted – backup regularly, and keep older backups for a while.

5 Lightroom needs to know where the files are – don’t move or rename files outside of Lightroom unless you understand exactly what you are doing, i.e. in Explorer or Finder, otherwise you’ll have a long job fixing all of the links.

6 Lightroom will not match your cameras rendering when working with raw files as it’s just raw data, but you can use the camera calibration profiles to emulate the manufacturer’s look for some cameras, or you can build your own profile to match.

7 Lightroom offers a choice of different colour spaces when you output, and AdobeRGB/ProPhotoRGB will look odd in programs that aren’t colour managed (like web browsers). Use sRGB for screen output like emailing or uploading to the web.

8 Lightroom’s Grid view behaves differently to other views – anything you do in Grid view applies to all selected images, whereas other views only apply to the most selected image.

9 Lightroom has 3 different levels of selection, not 2. Notice the difference, otherwise you could accidentally apply a setting to multiple different images.

10 Lightroom’s Flags are local to the folder or collection, whereas star ratings and labels are global. This means that a photo can be flagged in one collection but not flagged in the folder.

11 The first view of an imported Raw file before Lightroom renders its own preview often disappoints new users of lightroom.
What you first see is the camera produced jpeg, which has 'in camera' software adjustments applied, sharpening, contrast, saturation etc (depending on what settings you have programmed the camera to apply)
Then almost instantly, Lightroom renders its own jpeg preview, which is an accurate portrayal of how the raw file would look if converted to a jpeg without any extra enhancement at all.

The idea being that you apply your own editing to a the blank canvas of the raw image, rather than rely on the cameras idea of how the image should look.

12 Don't export your images to edit in "Photoshop etc", use the preferences to set up "Photoshop etc" as an external editing programme and then use the Lightroom 'Edit With' function, then, when you have finished editing, use the 'Save' function (and not 'Save As') to return your edited copy to Lightroom.


Now see if the answer to the question you are about to post can be found on the Adobe Lightroom FAQ site or in Adobe community help, by clicking F1 whilst running Lightroom
Originally posted at 12:00PM, 31 December 2007 PDT (permalink)
Harry Limey (a group admin) edited this topic 7 months ago.