Pages: [1]   Go Down

Author Topic: Thumb Cache  (Read 6920 times)

Nick Rains

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 705
    • http://www.nickrains.com
Thumb Cache
« on: July 19, 2006, 07:14:56 am »

OK, so I'm looking at the Windows beta here and LR seems to be building a cache of 3 different thumb sizes - small medium and large. I assume it's going to use these to help speed things up when moving from image to image.

Well, it's taken about 20 mins (so far) to complete this operation, and from DNG files too. I know DNGs include jpeg previews so my question is this: can LR use those previews? If not, why not? I don't have a ninja PC but a P4 3.2Ghz with 2Gb RAM is not a slouch either.

LR seems to be parsing every DNG file in the folder - 295 of them. This is unnecessary given that there is an updated version of the final file already embedded in the DNG file.

Photo Mechanic can pull this preview out in the blink of an eye and one can step through images as fast as one can press the keys, almost. I am trying to 'like' LR but if this is how it works then it is less than stellar as a workflow tool.

Maybe someone can point me the way but so far it looks glacial - even for a beta.

FWIW Photo Mechanic takes 47 secs for the same folder to finish working and the 100% previews are available right away. I know it's not showing me a 'perfect' representation of the processed DNG file but it's damn close and easily sufficient for checking sharpness.
Logged
Nick Rains
Australian Photographer Leica

61Dynamic

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 1442
    • http://
Thumb Cache
« Reply #1 on: July 19, 2006, 10:27:00 am »

LR won't be using the embedded DNG thumbnails from what I've gathered for two reasons.

1. The previews LR uses are larger than what's embedded and so it'll build it's own unique previews just as Bridge does.

2. The previews need to represent its default development settings of the raw files.

At this current point in time LR is not embedding the metadata into the DNG and I believe it is the same for thumbnails. I'm sure this will change in time but that won't change the fact that thumbnails will need to be rendered by LR anyway when files are imported.

The embedded thumbnails are not really there for use by Adobe's applications but for the use of third-party programs such as Photo Mechanic.
« Last Edit: July 19, 2006, 10:28:11 am by 61Dynamic »
Logged

Nick Rains

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 705
    • http://www.nickrains.com
Thumb Cache
« Reply #2 on: July 19, 2006, 05:45:44 pm »

Quote
LR won't be using the embedded DNG thumbnails from what I've gathered for two reasons.

1. The previews LR uses are larger than what's embedded and so it'll build it's own unique previews just as Bridge does.

2. The previews need to represent its default development settings of the raw files.

[a href=\"index.php?act=findpost&pid=71120\"][{POST_SNAPBACK}][/a]

DNG Previews are the same size as the final file, or at least they can be depending on your choice at the time of conversion.

I take your point 2 above though.

The thing is, if LR takes so long to generate different size thumbs it should subsequently be quite quick to view the images. It's not, it still takes up to 10 secs to complete the change from one image to the next when viewing at 100%.  The 'working...' message is on the screen for this time - I wonder what it's doing when the rendered thumb should already be available from the cache.

I give LR 9/10 for features - I really do like the processing controls but I can only give it 2/10 for performance. Let's hope this improves dramatically.

Does anyone know if there is any way to export the cache? It would be handy to be able to back up LRs 'database' of cached thumbs.
Logged
Nick Rains
Australian Photographer Leica

Ian Lyons

  • Full Member
  • ***
  • Offline Offline
  • Posts: 127
Thumb Cache
« Reply #3 on: July 19, 2006, 06:57:39 pm »

Quote
Does anyone know if there is any way to export the cache? It would be handy to be able to back up LRs 'database' of cached thumbs.


This folder can get VERY big. You can copy it to another hard disk or even a DVD (assumes it's not too big). In other words, be aware that a few thousand images could easily result in a thumbs folder that won't fit on a DVD.

For backup you also need to be looking at the Library.aglib file because it contains all your settings, metadata, etc. You can always rebuild the thumbs, but once the Library file is gone you're in deep smelly stuff.
« Last Edit: July 19, 2006, 06:57:57 pm by ilyons »
Logged

Nick Rains

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 705
    • http://www.nickrains.com
Thumb Cache
« Reply #4 on: July 19, 2006, 07:36:32 pm »

Quote
This folder can get VERY big. You can copy it to another hard disk or even a DVD (assumes it's not too big). In other words, be aware that a few thousand images could easily result in a thumbs folder that won't fit on a DVD.

For backup you also need to be looking at the Library.aglib file because it contains all your settings, metadata, etc. You can always rebuild the thumbs, but once the Library file is gone you're in deep smelly stuff.
[a href=\"index.php?act=findpost&pid=71192\"][{POST_SNAPBACK}][/a]
Thanks Ian

Interesting, IView's database of thumbs, based on 800px wide previews, occupies, for me at least, 1.2Gb for 13000 images. Bigger previews are not really needed as it is a DAM not a browser but it can pull out a full size preview from online files quite well.

This is one area where I think LR falls short. It needs full DNG/RAW metadata compatibility so the Library file becomes somewhat redundant, at least for archived DNGs. All settings and metadata must be included in the file itself otherwise it is just asking for trouble to store the info elsewhere.

IView is the DAM of choice these days and if you synch the annotations with the originals, either RAW or DNG, then even if you lose IView's database file you can still rebuild from scratch quite easily. It takes about 2 hours to catalogue about 13000 images - no big deal.

I strongly disagree with any approach that separates any information about a file from the file itself. This is why LR can never be a decent DAM until it addresses this issue. I have said this before but I still think LR is trying to be too many things at once and so is doomed to be mediocre at each task, with the possible exception of the actual RAW processing which is excellent.

Are there any photographers out there who use LR as their sole tool of choice? Do people like Jeff Shewe and the other developers/testers really use LR in their work by choice or because they are heavily involved with LR's developement and therefore must be seen to be using it.

I have to say that if it wasn't for Jeff and co, whose opinions I respect greatly, I would not even be trying to like LR, it would be deleted as a 'close but no cigar' app.
Logged
Nick Rains
Australian Photographer Leica

61Dynamic

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 1442
    • http://
Thumb Cache
« Reply #5 on: July 19, 2006, 09:44:01 pm »

Quote
DNG Previews are the same size as the final file, or at least they can be depending on your choice at the time of conversion.

I take your point 2 above though.

The thing is, if LR takes so long to generate different size thumbs it should subsequently be quite quick to view the images. It's not, it still takes up to 10 secs to complete the change from one image to the next when viewing at 100%.  The 'working...' message is on the screen for this time - I wonder what it's doing when the rendered thumb should already be available from the cache.

I give LR 9/10 for features - I really do like the processing controls but I can only give it 2/10 for performance. Let's hope this improves dramatically.

Does anyone know if there is any way to export the cache? It would be handy to be able to back up LRs 'database' of cached thumbs.
[a href=\"index.php?act=findpost&pid=71183\"][{POST_SNAPBACK}][/a]

You're right, the DNG preview is full size when set to "Large" however, its not full quality. I know for a fact, Bridge ignores embedded jpegs and LR certainly has to in order to render the quality level required for the edits it can do.

It's not fair to judge performance of LR just yet. It's still beta software and work is still being done to it. It would be a big waste of time for them to optimize the software's performance now as the effort could be rendered moot with further changes. With each beta release, it does gain in performance and by 1.0 stage, they (those at Adobe) have stated things will be much much better than they are now. Optimization is always handled last in software development.

The DB can be backed up. Look in the preferences and you'll see an option to set the DB location. Simply back that folder up as well as the preference file as mentioned.

Quote
It needs full DNG/RAW metadata compatibility so the Library file becomes somewhat redundant, at least for archived DNGs.

...

I strongly disagree with any approach that separates any information about a file from the file itself. This is why LR can never be a decent DAM until it addresses this issue. I have said this before but I still think LR is trying to be too many things at once and so is doomed to be mediocre at each task, with the possible exception of the actual RAW processing which is excellent.
That's a bit of a premature judgment IMHO. Without question, better XMP metadata support is coming. You can set an option to export the metadata automatically for each file. It saves it as a XMP file with the original. It just hasn't gotten to the point it embeds it into the DNG files themselves (the xml code is still being refined).

Quote
Are there any photographers out there who use LR as their sole tool of choice?
I know Michael has said he does and I know Martin Evening does too. I will as soon as the organizational structure of the Shoots match what's on the hard drive.
Logged

Nick Rains

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 705
    • http://www.nickrains.com
Thumb Cache
« Reply #6 on: July 20, 2006, 12:47:33 am »

Quote
That's a bit of a premature judgment IMHO. Without question, better XMP metadata support is coming.
[a href=\"index.php?act=findpost&pid=71211\"][{POST_SNAPBACK}][/a]

I know, and I live in hope. Let's see if they can bring it off!
Logged
Nick Rains
Australian Photographer Leica

jani

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 1624
    • Øyet
Thumb Cache
« Reply #7 on: July 20, 2006, 03:20:03 am »

Quote
Optimization is always handled last in software development.
Yes, it's a sorry state of affairs.

But then again, if it wasn't handled last, it wouldn't be called "optimization" anymore.
Logged
Jan
Pages: [1]   Go Up