How about if the image is opened in Photoshop or saved out, does the noise reduction stick or not? It may be just an ACR display issue.
I can't reproduce this on a PC with Camera Raw 6.5.
Maybe you should do some screen grabs and put them up to show exactly what you're seeing.
Tom Pinkerton wrote:
…3) Apply Noise Reduction (Luminance:30; Lum Detail:75; Lum Contrast:0; Color:25; Color Detail:50).
4) Go to Adjustment Brush and set a non-zero Exposure value.
5) Apply brush to image and notice the Noise Reduction effects disappear (noise returns).
6) Click Clear All button to clear Adjustment Brush and Noise Reduction works again.
This seems to only happen with Adjustment Brushes with a non-zero Exposure value (applying brightness or other settings don't seem to produce the problem)…
I would absolutely expect an Exposure adjustment of any kind to have an effect on noise. The first thing that comes to mind is to apply any such brush adjustment before any noise reduction.
Beyond that, it's possible that the noise reduction ceases to be visible while you are working with the brush, but does it return once you leave the adjustment brush tool or not?
Wish I had a noisy Canon image file to experiment with , maybe you could post one?
However, above all, it seems only natural to apply any brush adjustment before any noise reduction.
Just my ¢2.
Wo Tai Lao Le
People with Canon cameras are pickier than people with whatever kind of camera you have, Ramon. What we call "unacceptable noise" you call "character" in your images. Just kidding!
And as far as I know the order in which you apply things in Camera Raw doesn't affect the rendering.
Richard (and others),
Yes, very good idea to check that. The problem does indeed get applied to the full sized, opened image as well as to the display previews. After working with this more, I now notice that I was wrong to say that the entire noise reduction is cancelled - rather it "changes", sometimes subtly, sometimes more dramatically depending on what the noise reduction settings are set to. Further, how dramatic the "changes" appear depend greatly on the preview zoom (the changes are more subtle at 100%, but it can look like the noise reduction is completely turned off at 50% and 66%).
Now I realize that the noise reduction does not ordinarily display at all preview sizes (especially smaller ones), but this is different. At preview sizes where it does normally get applied, applying an adjustment brush with any non-zero exposure value (even just +0.05) can have the appearance that the NR is completely turned off for the whole image. Simply nudging the exposure value back to zero brings all the noise reduction back.
Also, to be clearer and avoid confusion for others, the change in noise I'm seeing is not localized to just the brushed spot. Obviously if one increases exposure, you'd expect to potentially see more noise. Instead, what I'm seeing happens to the entire image, even if I simply paint a single small brush dot, say in a far corner. Having the image change globally in response to painting a small spot with the adjustment brush cannot be a correct result. Further, this does not happen with any of the other adjustment brush settings like brightness, contrast or saturation. There must be something unique about the exposure setting that perhaps introduces a new step into the processing pipeline, and this step is affecting the entire image.
In any case, the problem only seems to be an issue in somewhat extreme cases and is less noticeable at 100% (and the finally opened image). It's more just annoying when previews are generated for viewing in Bridge, for example.
I suppose one alternative might be to rob a bank and go buy one of those new 1D X's. Then maybe I wouldn't have to worry about noise anymore.
Thanks for the responses!
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I tried to reproduce what you did with a high ISO night shot of my own, using the same settings you chose, and I couldn't get any more noise to show. Perhaps it's camera-specific or system-specific. There may be stuff that kicks in or out depending on performance to speed up the display of zoomed-out data, but in your case since you say the noise actually makes it into the converted image, it sounds like a bona fide bug!
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There was a similar issue concerning usage of brush. Changing exposure of the brush to nonzero value changed rendering of the highlights of the whole image (not just brushed part). I reported it here I think a year ago and Eric responded it was a known issue and limitation of current implementation of the brush. I don't know was it addressed in last versions (didn't try)
However, I also tried to reproduce this NR issues, but on 32bit XP version it seems to be ok (and images from my Canon compact cameras are obviously quite noisy)
I attempted to reproduce this with some other images from different shoots (but same camera) and could not reproduce it. Clearly there are additional variables to this that I haven't isolated. Interestingly, I have seen this problem manifested primarily as changed highlights rather than noise changes, so I wonder if it isn't related to the same issue that Vit mentioned. The files that are subject to this problem happen to be older DNG converts that were also recently updated to the current 2010 process setting. I'm not sure if that might have anything to do with it. In any case, I clearly have more digging to do in order to isolate the key variables. I appreciate the help and will pass along any updates if I learn anything new.
There are some known issues with the local exposure adjustment leading to global changes in image appearance, notably in the highlights. The issue with noise should already be fixed with the ACR 6.6 release candidate (RC), currently available.
Thank you very much! ACR 6.6 RC fixed the main problem with 100% previews and in the final renderings. I still notice the noise switch on and off at certain other larger preview sizes, but I'm not particularly concerned about that. I appreciate the help!
The issue Tom describes continues to happen with my raw files. I convert Canon cr2 files to DNG on import. If I use the graduated filter or adjustment brush in Camera Raw to make exposure adjustments, noise reduction is cancelled in the preview unless I am adjusting a slider. In other words, while I am physically moving a slider, noise reduction is applied, but when I release the slider, noise reduction is cancelled, although it is again applied when I save the image to jpeg. This makes it extremely difficult to work on high ISO images. I have updated to ACR 6.6. That did not help. Any suggestions?
For the purposes of evaluating noise reduction, the current solution is to zoom to 1:1. NR will always be applied in that case, and it will be the most accurate rendition for the purposes of evaluating the quality of the NR.
Thanks, Eric, but the issue is not evaluating noise reduction; the issue is working on other aspects of the image in other panels. For instance, in the Basics panel, after I have used the adjustment brush or graduated filter, no noise reduction is applied unless I am adjusting a slider. When I release the slider, noise reduction is cancelled. This makes it very difficult to make basic adjustments such as exposure and contrast. Why is noise reduction cancelled in the preview after using the adjustment brush or graduated filter?