LR soooo long to convert to B&W

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Why is Lightroom so long to convert a bunch of pictures to B&W ? For instance I've converted 250 colors pictures to black and white with the V keyboard shortcut, it took about 2 or 3 minutes for all the pictures to be converted! Is it the same for you ? Isn't it too long ?
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ERIC BURLET

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  • frustrated, again !

Posted 4 years ago

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Rob Cole

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It shouldn't take more than a few seconds or so to apply the settings (i.e. have them accepted / committed to the catalog / undoable ... ), but it can take much longer for all the previews to be re-rendered (i.e. to have all b&w renderings finalized for viewing in Library grid or filmstrip).
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Rikk Flohr, Champion

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248 Canon 5DMKII images took 16.56 seconds here.
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Rob Cole

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How did you measure that with such precision?
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Rikk Flohr, Champion

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Stopwatch
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Rob Cole

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I just tried - took about 6 or 7 seconds to process 126 photos, using this as reference:



Note: after processing, it took a few minutes for all previews to be re-rendered, as evidenced by visual inspection in grid view.

Eric, are you talking about processing time or preview re-generation time?
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ERIC BURLET

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Rob, you're right !The set treatment is pretty fast on my computer also, this is the preview regeneration time that takes so long. And for all batch changes, not only for b&w actually !
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Rikk Flohr, Champion

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249 DNG Files from Canon 7d/5dMKII 50.92 Seconds to generate BW previews and update entire grid of thumbnails.
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ERIC BURLET

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You're a lucky man Rikk...

In my case it's canon raw files, maybe it's different
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Rikk Flohr, Champion

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Tried Raw Files. Within one second of the same time. I have two win and two mac and with the exception of the 4-5-yo Macbook. The times are very similar. I think looking at your system specs is about due. Care to share your machine specs, os, and location of critical LR files?
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ERIC BURLET

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No problem :

Win 7 64 bits
Intel Core I7 Extreme 980X
Motherboard : Intel DX58SO
RAM : 12 Go of DDR3
ATI FirePro V4800

Catalogs and previews are on a dedicated SSD Samsung 840Pro 480Go
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Rikk Flohr, Champion

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Location of Image files?

Your machine actually exceeds mine's specs by quite a bit.

I don't even have an SSD
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ERIC BURLET

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Yes, this is a racing car and it runs pretty smoothly otherwise)... Files are on a another hard drive inside the computer, not SSD
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Rob Cole

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Eric,

In general, it takes Lr at least 2-3 seconds (average) to render a raw (which has some settings applied) even in the best case scenario. So, in general, it's not unusual for 250 raws to take several minutes to render. I chose 126 for my previous experiment because that's the maximum number that I can see at once in the grid, and Lr won't automatically re-render previews for photos that aren't visible.

I just did another experiment:
* Assured 1:1 previews were discarded.
* Rebuilt 60 1:1 previews

These were well-edited (Nikon D300 raw) photos, with locals, lens corrections, noise reduction ...

It took about 6 minutes to complete, so about 6 seconds per raw average - measuring time until this progress scope completed:


All 4 cores alternated between 100% utilization and way less than 100% utilization (typical).

I've compared performance to other Lr users a fair amount and consider my Lr performance to be normal and fairly average these days. I discard data points which seem inexplicably high or low, considering these to be abnormal or misunderstood...

So according to my experience, your performance does not seem unreasonable - for 250 photos, I would expect time to apply treatment of a few to several seconds and time to re-render all anew afterward: a few to several minutes. PS - Lr is not especially slow about this: *all* raw processors take a long time to re-render raw files, including NX2, DxO, etc. - granted: some are faster than others and how fast depends on system and settings........

If you plan to compare your results to anybody else's, I recommend finding a way to be 100% certain you are measuring the same thing, the same way...

Rob
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Rob Cole

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PS - If I had 6 cores it would have been faster (since all 4 cores were at 100% some of the time), but 8-12 cores wouldn't improve things much beyond that - there is a limit to how fully Lr can utilize multi-core processors.
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Rikk Flohr, Champion

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Using Rob's methodology on my system:

12 Cores
12 GB of Ram
Win 7 64 bit
Internal 7200RPM Drives for Catalog/Previews - Images are on 7200RPM USB 3.0 External drives.

I build 1:1 Previews at the rate of 28 images per minute. Slightly more than 3X Rob's speed

I build Standard Previews at the rate of 170/ Minute. (1440 px)

That said, 1:1 preview speed is not a limiting factor on converting a batch to Black and White and then looking at them one by one. I think an expectation of what you want to be able to do is in order:

Do you want to:

1. Merely do the conversion?
2. See the thumbnails?
3. Begin working on an image at random?
4. Have 1:1 Library Previews to evaluate?

1-3 happen in seconds. 4 takes minutes. When you speak of 3 minutes how far does that get you?