jeffrey_hirschl's profile

15 Messages

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514 Points

Sun, Jun 23, 2019 12:58 AM

Lightroom Classic: Dehaze performance with monochrome images.

I just (6/22/19) noticed this same behavior (painfully slow response from sliders after adding positive dehaze) on two monochrome images in Lr Classic release 8.3.1 (LATEST VER). Unsure if it went away in the earlier release and then came back, or if it has been there all along. Please revisit and if you can duplicate, please repair in future release. Thanks. I will supply affected pictures if you need them - please ask on this forum.

Note: This conversation was created from a reply on: Lightroom CC 1.3: Dehaze tool causing lag following update to 1.3.

Responses

15 Messages

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514 Points

2 y ago

Please let me know if this thread is still being monitored, or if I should start a new thread on this issue. Also please let me know if you can duplicate, or if you want me to supply the pictures affected by this issue. Thanks!

Champion

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2.3K Messages

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38.6K Points

2 y ago

I'm not seeing any issue with Dehaze applied using CR2 files with 'Treatment' 'Black & White' conversion. What type of image files are you using and how are they being converted to monochrome? Are the Basic panel controls slow if you hit the master Reset button at the bottom of the Develop panel and then apply ONLY Dehaze? If so I suggest providing a share link to one of the files exported to DNG file format, which will have all your settings embedded.

15 Messages

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514 Points

2 y ago

I posted two images at: https://www.dropbox.com/sh/v5zdowngvp2z6iu/AAAmAuNhWaxtluZmt3XQvL6Sa?dl=0 .

These are original monochrome as scanned - images are from an old camera and analog media. Eiffel Tower #2 has quite a few adjustments, including considerable dehaze. Try moving the Black and White sliders and note considerable lag. However, if the dehaze is set to zero, there is literally no lag at all. In Eiffel Tower #2-2 I took a virtual copy, did reset and only put in the dehaze. When moving the black and white sliders here, there is only a modest, but very noticeable amount of lag. But when dehaze is removed completely, there is barely any lag at all. Looks like the lag with dehaze put in is modest with no other adjustments but gets much, much worse when more adjustments are added.

BTW, the computer here is a i7-8700 with 16GB RAM in case that info is needed.

Thanks for taking the time to look at this and for volunteering as a champion on the site.

Champion

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2.3K Messages

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38.6K Points

2 y ago

I'm using a similar i7-8700K system with 32GB memory and see the same lag. Dehaze is a very processor intensive image control that interacts with all of the other Basic panel Tone controls. When using Dehaze I always see a small lag in rendering when adjusting any of the Develop controls. You have applied a number of Spot Removal Clone Heal spots to the Eiffel Tower #2.DNG file, which is causing the additional delay. Try applying Spot Removal as the last step in your Develop adjustments and the control delay should be more tolerable.

If these are TIFF scanner files I would do the spot removal in PS using the Spot Healing Brush, which works much better than the LR Spot Removal tool for this purpose. I would also apply Auto Levels using the below settings. You could even apply the Dehaze setting in PS using the Camera Raw Filter, but perform these operations BEFORE importing the scanner files into LR. Then you won't need to use the Dehaze control inside LR. Just keep in mind these are destructive edits, which can't be undone once the PS file is closed.

BTW- It appears your scanner files are 8bit (see Histogram below. For best results and to prevent posterization set your scanner software to create 16bit/channel TIFF files.

15 Messages

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514 Points

2 y ago

Thanks for all of the information. I opened a random color image and noticed that applying dehaze as my first adjustment caused almost no perceptible lag in the black and white sliders afterward. But applying dehaze as a first adjustment on the Eiffel Tower image here does cause perceptible lag. It might be that all of the inherent noise in this image results in more processing needed on succeeding adjustments once dehaze has been applied. Don't know. Since Adobe had some problems previously with dehaze (see predecessor thread to this one), I thought they might want to know about this issue. I'll continue to monitor this as I edit monochrome images and report back if I see the same result on other, less noisy native-monochrome images.