Smart previews file....

AlexM74

New Member
Joined
Dec 5, 2018
Messages
19
Lightroom Experience
Advanced
Lightroom Version
6.x
Lightroom Version
12.0.1
Operating System
  1. macOS 12 Monterey
Hi!
I'm using smart previews as an additional backup of my images. I duplicated the catalog in an external disk and started generating the standard previews, but I noticed something strange: the images are all raw, and while generating the first 20,000 or so the file has grown by about 5 gb.
Then the next day I launched the generation of another folder with about 20,000 others and the smart previews file didn't grow and the opening date didn't even update!
The smart previews would appear to be generated correctly, but how is this possible if the relative file seems not to have been used?

Thanks!

Alex
 
Joined
Nov 27, 2013
Messages
2,047
Location
Queensland
Lightroom Experience
Intermediate
Lightroom Version
Classic
First let me state- Smart Previews are NOT a method to backup images!
The only 'true' file backup is a copy of the original camera files on another physical drive.
Although Smart Previews could be used in a catastrophe if you lost ALL original files, they do not maintain filenames, and are all reduced in size to 2560px (long edge).

Forget about 'backing up' Smart Previews. Instead concentrate on the Original files and Catalog backups.
 
Joined
Jul 2, 2015
Messages
12,711
Location
Netherlands
Lightroom Experience
Power User
Then the next day I launched the generation of another folder with about 20,000 others and the smart previews file didn't grow and the opening date didn't even update!
The Macintosh Finder can indeed not pick this up, especially with the new APFS disk formatting. I have seen the same thing. Lightroom Classic will tell you how large the smart previews package really is. And Rob is right: smart previews are not suitable as a backup system.
 

AlexM74

New Member
Joined
Dec 5, 2018
Messages
19
Lightroom Experience
Advanced
Lightroom Version
6.x
Hi and thanks for the replies
let me explain my "backup strategy": I'm talking about 500.000 raw files, more or less, so few more than 10TB, I have one copy on my working drive, one full backup on an external drive, and then I make a third copy, bringing this disk out of my house. So the first backup is to protect from disk failure, the second is to protect from both disk unavailability (fire, theft, ecc...). That's why I use smart previews: the risk is not so high and it could be very expensive to have 3x12Tb disks.....
The Macintosh Finder can indeed not pick this up, especially with the new APFS disk formatting. I have seen the same thing. Lightroom Classic will tell you how large the smart previews package really is. And Rob is right: smart previews are not suitable as a backup system.
that's not clear to me...... what does it mean that finder can not pick it up? where is LR writing smart previews?
 
Joined
Nov 27, 2013
Messages
2,047
Location
Queensland
Lightroom Experience
Intermediate
Lightroom Version
Classic
what does it mean that finder can not pick it up?
I believe Johan is answering your statement- "file didn't grow and the opening date didn't even update! " by suggesting that Smart Previews do not exist in a regular Folder, but instead, are a 'Cache' controlled by LrC, thus not having all the characteristics of regular OS folders.
 
Joined
Jul 2, 2015
Messages
12,711
Location
Netherlands
Lightroom Experience
Power User
Correct. Smart previews are a so-called ‘package’, which is basically a folder that looks like a file and can be double clicked to launch an application like a file. But because it’s a folder the Mac Finder can be very wrong about size and modification date.
 

Conrad Chavez

Lightroom Guru
Lightroom Guru
Joined
Nov 30, 2012
Messages
860
Lightroom Experience
Power User
Lightroom Version
Classic
If you want to see what’s inside any macOS package file, right-click it and choose Show Package Contents.

The picture below is of a Smart Previews package I opened on my Mac, containing Smart Previews of 7MB Canon CR2 raw files. You can see that the organization and filenames don’t correspond at all to the originals, making it much more difficult to locate the image you want — many would say totally impractical to use — compared to a real backup.

Lightroom-Classic-Smart-Previews-package-opened.jpg


(Apple uses the same package method to store the media you add to Apple Photos, but their package file is called Photos Library.photoslibrary in the Pictures folder.)

I think Adobe uses Lossy DNG for Smart Previews. So another way to achieve the kind of space-saving backup you want is to maybe set up a Publish Service that exports Lossy DNG copies. That would preserve your original filenames. To also preserve your folder hierarchy, you probably need to add a plug-in such as Folder Publisher or LR/Tree Exporter.
 

AlexM74

New Member
Joined
Dec 5, 2018
Messages
19
Lightroom Experience
Advanced
Lightroom Version
6.x
ah ok, so tha size and opening date is wrong but the previews are within that file/folder! So my third-backup should work :)
i've tried also exporter plugins but I've never found one working: one crashes, the other renames file, ecc....
 
Top