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ACR Cache

Feb 20, 2012 6:04 PM

Where is Lightroom's ACR Cache stored and what is it's name. I am trying to search for it  and can't find it.

 
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  • Currently Being Moderated
    Feb 20, 2012 6:52 PM   in reply to jljonathan

    Look in your Preferences:

     

    Preferences_2012-02-20_22-50-38.jpg

     

    Hal

     
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  • Currently Being Moderated
    Feb 20, 2012 8:53 PM   in reply to jljonathan

    jij, if you read the image that Hal provided, you'll see its not called ACR cache, its Camera Raw Cache

     

    You need to look in your Lightroom preferences to see where its stored, not on G:/ where Hal keeps his cache

    cache.png

    Default place for mac is above  and the folder it is in is called  Adobe Camera Raw.

     

     

    Hope that helps

     
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  • Currently Being Moderated
    Feb 20, 2012 10:06 PM   in reply to jljonathan

     

    grand

     
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  • Currently Being Moderated
    Feb 21, 2012 3:49 AM   in reply to hamish niven

    I'd be interested to know about all your experiences: how big do you define it and does it really make a difference?

     

    Any new observations with LR4b vs. LR3.6?

     

    In LR3 I had assigned *generous* 70GB, but never felt that I got equivalent benefit...

     
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  • Currently Being Moderated
    Feb 21, 2012 3:56 AM   in reply to Cornelia-I

    I set mine to about 25Gb, simply as I'm trying to keep at least 50Gb free on my laptop at any one time.

    I also am unsing LR3 and LR4 which I'm loving, so most days I delete the cache on startup as I swap between each version of LR.

    My logic is that they are different programs, have different processses 2010 - LR3x and 2012 LR4, so the cache may get confused or when LR starts to slow down - usually after about 4 hours of work.

     

     

    I periodically check the size and usually delete when my laptop gets to around 50-70 Gb as I mentioned.

     

     

    does that help?

     
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  • Currently Being Moderated
    Feb 21, 2012 4:29 AM   in reply to Cornelia-I

    When I had my current desktop built a couple of years ago I had 4 internal drives installed so that I could 'dedicate' a drive to each of the major LR elements (program, catalog/previews, ACR cache, pictures)....so as I have the space, in LR3 I allocated the max (200gb) for the ACR cache, and have done the same for the LR4beta.

     

    Was it worth doing (bearing in mind the additional cost of the drive was peanuts)? No real idea, I've never tried to setup what would be some quite complicated testing to find out. Suffice to say, I've always been happy with the speed of operation in Develop, but would I notice a difference with a much smaller ACR cache? Possibly not, but again that would largely depend on how far back into the archives I wanted to go. Assuming 'not very far', I doubt very much that reducing the size of the ACR cache to somewhere between 20 and 50gb would make any noticeable difference. With a fast processor and a lot of RAM and images on fast internal drives, chances are that an image will load into develop pretty quickly even if there was no ACR cache entry available. But on a slower system, maybe it would be a different story.

     

    One interesting (to me at least) observation is that 'loading' in LR4b Develop seems different to LR3. In the latter, there is typically a noticeable gap between sliders being 'activated' (sub-second) and the 'loading' indicator disappearing (2-3 seconds) on Canon 5DII images. With LR4b both events are sub-second (if anything the 'loading' indicator goes away a fraction of a second before the sliders are activated)....the overall impression therefore is that this aspect of work is quicker in LR4b.

     
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  • Currently Being Moderated
    Feb 21, 2012 4:39 AM   in reply to hamish niven

    Thanks for your quick answer, Hamish!

     

    It certainly helps to open my eyes to a potential new conflict during running LR3 and 4b alternatively on the same computer...!

     

    But I might have a general misconception: somehow I would expect that this ACR cache is a bit like the previews of LR: what the latter do in speeding up Library module/loupe view and Slideshow etc. the former should do for shortening the time of loading overlay when opening in Develop.

    And do that repeatedly, as long as the required detailed dev-view would be contained in ACR-cache, so hopefully for many development sessions.

    So I never intended to throw them away without dire need...

     

    Your handling suggests that you do not expect this to be very much the case, and you getter better development loading speed results by regularly emptying it in favour of space left on your disk?

     
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  • Currently Being Moderated
    Feb 21, 2012 4:52 AM   in reply to Cornelia-I

    I find LR speeds up when I delete the cache yes, but that is when I've seen LR drop in speed.

     

    The potential conflict that I wondered about is actually 2 catalogs using the same cache, rather than potential conflict in duplicate previews of the same image in LR3 and LR4

     

    What I've noticed is that my laptop starts running at 70-90ºc soon after I get into develop mode, and even more so in the exporting jpegs etc.

     
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  • Andrew Rodney
    1,387 posts
    Apr 16, 2009
    Currently Being Moderated
    Feb 21, 2012 7:13 AM   in reply to hamish niven

    Note that if you use the newer DNG spec which provides a fast load preview, the need for the ACR cache (which is a rolling cache based on your preferences) isn’t really necessary. Further, if you don’t store the ACR cache with the images and say you move them to another machine, the ACR cache files are back on that other machine. Not the case with the DNG!

     
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  • Currently Being Moderated
    Feb 21, 2012 8:25 AM   in reply to Andrew Rodney

    I did not quite get what you mean that my ACR cache should be concerned by a move of my images: my ACR cache is on a *fixed default location*, which is "C:\Users\<my user>\AppData\Local\Adobe\CameraRaw\" on my Windows7-system.

    Are you saying that if I move my actual images from the laptop to the NAS the ACR-cache-entries would no longer be found? Different than for the catalog entries who just update their pointer as long as I do the move inside LR or update position after move in OS?

     
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  • Currently Being Moderated
    Feb 21, 2012 8:38 AM   in reply to hamish niven

    I have seen a way to separate the ACR-caches used for LR4b from the one for LR3.6:

    Just create a new empty folder "cache4" let's say parallel to "cache" for LR3 and specify it in the LR4b preferences.

     

    What keeps me astonished though is that it does not get filled as I had assumed:

    I did look at 3 images in develop module, waiting until the overlay "loading" was finished, but it stayed empty.

    Then I did some real develop edits to a fifth image, and moved on the the next image, but still empty !

    No update in the original cache folder either.

     

    Yes, I do include the "fast load preview" in my DNG-references in LR4b as suggested by Andrew, but had done so from the beginning.

    Still the old cache-folder had been hijacked from LR4b over LR3, as I can see from previous date-time stamps there.

     

    Does anybody understand this? So when is LR4b supposed to write to its ACR-cache, with "Embed Fast Load Data" ticked in preferences?

     
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  • Andrew Rodney
    1,387 posts
    Apr 16, 2009
    Currently Being Moderated
    Feb 21, 2012 8:53 AM   in reply to Cornelia-I

    Cornelia-I wrote:

     

    I did not quite get what you mean that my ACR cache should be concerned by a move of my images: my ACR cache is on a *fixed default location*, which is "C:\Users\<my user>\AppData\Local\Adobe\CameraRaw\" on my Windows7-system.

    Are you saying that if I move my actual images from the laptop to the NAS the ACR-cache-entries would no longer be found? Different than for the catalog entries who just update their pointer as long as I do the move inside LR or update position after move in OS?

    If you move your catalog and images to another machine, how can they have access to the Cache? They can’t, the cache is rebuilt kind of defeating the purpose. If instead the DNG contains the similar data (for a quicker preview experience in develop), so much the better.

     
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  • Currently Being Moderated
    Feb 21, 2012 9:03 AM   in reply to Cornelia-I

    Cornelia-I wrote:

     

    I have seen a way to separate the ACR-caches used for LR4b from the one for LR3.6:

    Just create a new empty folder "cache4" let's say parallel to "cache" for LR3 and specify it in the LR4b preferences.

    I don't believe this will work, as the ACR cache location is not stored within the LR preferences (which are separate betwee LR3 and LR4), but in the CameraRaw preferences (which are shared).

     

    Beat

     
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  • Currently Being Moderated
    Feb 21, 2012 9:40 AM   in reply to b_gossweiler

    True.... I closed LR4b and opened LR3, just to find that these settings had been switched there also...

     

    But do you know when this cache is supposed to be written to, Beat?

     
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  • Currently Being Moderated
    Feb 21, 2012 1:09 PM   in reply to b_gossweiler

    What about the default develop settings per camera & ISO?

    Are these specific to either LR3 or LR4b or is this another secretly shared common setting?

     

    ...I would really hope not, because my cameras need different settings... at least I could fix this safely by including the PV ?

     
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  • Currently Being Moderated
    Feb 21, 2012 1:54 PM   in reply to Cornelia-I

    Cornelia-I wrote:

     

    What about the default develop settings per camera & ISO?

    Are these specific to either LR3 or LR4b or is this another secretly shared common setting?

     

    The ACR/LR Defaults are shared between LR and ACR...and it's based on the camera metadata and can be segmented by serial number and/or ISO.

     
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  • Currently Being Moderated
    Feb 21, 2012 2:20 PM   in reply to Cornelia-I

    Cornelia-I wrote:

     

    But do you know when this cache is supposed to be written to, Beat?

    The ACR cache is being written when an access to the original (not only to the preview) image is needed, and no entry for that image is present in the cache already. This is typically the case in develop, but also when exporting, printing, or building the previews.

     

    Beat

     
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  • Currently Being Moderated
    Feb 21, 2012 2:25 PM   in reply to Cornelia-I

    Cornelia-I wrote:

     

    What about the default develop settings per camera & ISO?

    Are these specific to either LR3 or LR4b or is this another secretly shared common setting?

     

    ...I would really hope not, because my cameras need different settings... at least I could fix this safely by including the PV ?

    You can see what's stored in the ACR Preferences by looking at the following file with any text editor (Win7/Vista path):

    %appdata%\Adobe\CameraRaw\Defaults\Preferences.xmp

     

    Within the same folder, you'll find files called "Default_xxxxxxxxxx.xmp", which are the ACR default settings, separated by camera model. If you have "Make defaults specific to camera serial number" and/or "Make defaults specific to camera ISO setting" checked in the LR Preferences (Presets tab), you'll see a "Default_xxxxxxxxxx.xmp" for each combination of these.

     

    Beat

     
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  • Currently Being Moderated
    Feb 22, 2012 1:35 PM   in reply to b_gossweiler

    That remains strange: I did several more edits in develop now, but the cache-folder still stays empty, as if LR4b would not write to it at all.

    Nor does LR3 !

     

    The last files inside this cache folder stem from before I switched to using LR4b on this machine.

     

    But both preferences (LR4b as well as LR3.6) point to the same camera raw cache.

    I execute events which Beat mentions as writing to the cache.

     

    Any ideas what might be wrong?

     

     

     

    Looking at Preferences and Defaults  worked fine, thanks.

    Cornelia

     
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  • Currently Being Moderated
    Feb 22, 2012 2:00 PM   in reply to Cornelia-I

    New files in ACR cache are only produced if one does not already exist, and develop adjustments don't alter ACR cache files if they already exist. Try clearing the ACR cache and you'll see it being build up, or import new images.

     

    Beat

     
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  • Currently Being Moderated
    Feb 22, 2012 2:06 PM   in reply to b_gossweiler

    I do not need to clear the cache, because it is already empty.

    And has stayed so. So wherever a develop-preview may have been taken, surely not out of an empty folder...

     
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  • Currently Being Moderated
    Feb 22, 2012 2:27 PM   in reply to Cornelia-I

    Sorry, I missed that.

     

    Are you sure you're working with Raw images?

     

    Beat

     
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  • Currently Being Moderated
    Feb 22, 2012 3:05 PM   in reply to b_gossweiler

    Yeah - definitely ! I am very passionate about that and do not let any camera of mine create its own jpg. ;-)

     

    To be precise: I do DNG-conversion while importing, so I was working on DNGs when I expected to see new cache entries.

    With embedded fast load in LR4b, without obviously in LR3.

    Lossless DNGs.

     
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  • Currently Being Moderated
    Feb 22, 2012 3:40 PM   in reply to Cornelia-I

    What you describe makes sense for LR4 Beta with "embed fast load data" checked. The fast load data replaces the ACR cache in this case.

     

    But in LR3, as well as in LR4 Beta without "embed fast load data" checked, you should see an ACR cache entry created upon import with "Copy as DNG".

     

    Beat

     
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