RAW, ACR, and noise

mark moe said:

I don't know what the acronym ACR stands for... What is it??

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This is the raw convertor that is included in PS-CS or seperately for previous versions.

--
Victor Z

Anybody happen to meter an A2 the same way?

Jim N'AZ said:

Azure Feast said:

Jim N'AZ said:

Ok--why is ISO400 really 730?

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The point was already answered. Indeed ISO 160 is mostly accepted
as being the real ISO100 sensitivity of the A1. My tests gave the
results I indicated at ISO 400.

Jim N'AZ said:

You used neatimage. Was that on the final jpg or is it possible
for neatimage or some other noise reduction to work directly on the
raw data?

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No you cannot work on the RAW data. But with a photshop NR plugin
(Neat Image in my case) you work on the (White
balanced/Interpolated) data before any compression. So you don't
suffer from the "noise aggregation" that the JPG compression is
provoquing. The difference in noise reduction effectiveness is
spectacular.

--
Marc for Azure Feast

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Jim N'AZ

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I've been shooting at ISO 400 for my b/w photos and quite like the results. Yes, there's some noise, but it looks about the same as ISO 400 film grain.

For street photography, I don't have any issues shooting at ISO 400. For landscapes...well, I'll stick with ISO 100. ;-)



Larry

This was taken at ISO 400, xtra fine jpeg, handheld, no flash, with my A200. I used the noiseware plug-in. Even with some rather significant cropping I have printed this at 8x10 and it looks great!!!



--
Howard

Please visit my galleries at http://www.pbase.com/howardka

Looks like there was plenty of available light. There is a slightly soft quality to it, which is perfect for the subjects in this case. You could also sharpen and pop the color to provide a different feel to the picture.

Good job. Just shows that people tend to be overly critical of noise and not take into account that there are many things that can be done, both when taking the picture and in post-processing, to overcome significant noise.

This has helped remind me that I don't always "have" to shoot in ISO 64.

Howard Katz said:

This was taken at ISO 400, xtra fine jpeg, handheld, no flash, with
my A200. I used the noiseware plug-in. Even with some rather
significant cropping I have printed this at 8x10 and it looks
great!!!



--
Howard

Please visit my galleries at http://www.pbase.com/howardka

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Howard Katz said:

This was taken at ISO 400, xtra fine jpeg, handheld, no flash, with
my A200. I used the noiseware plug-in. Even with some rather
significant cropping I have printed this at 8x10 and it looks
great!!!

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Here is another ISO 400, xtra fine jpeg, handheld, no flash - A2. I just denoised and sharpened again last night and printed a gorgeous 8X10.



http://images.fotopic.net/?iid=y71q7k&outx=600&noresize=1&nostamp=1.jpg

I'm still playing around with the different noise reduction and sharpening techniques. Not real satisfied yet, but getting closer. I grumble a little about the post processing sometimes, but regardless, I'm getting shots with this camera that I probably would not have gotten with film.

Bea
--
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Ron,

Actually the light was pretty poor but, levels in PS helped with that. The softness is intentional I felt it was appropriate for this shot so I applied very little USM.

Howard

Kansas Ron said:

Good job. Just shows that people tend to be overly critical of
noise and not take into account that there are many things that can
be done, both when taking the picture and in post-processing, to
overcome significant noise.

This has helped remind me that I don't always "have" to shoot in
ISO 64.

Howard Katz said:

This was taken at ISO 400, xtra fine jpeg, handheld, no flash, with
my A200. I used the noiseware plug-in. Even with some rather
significant cropping I have printed this at 8x10 and it looks
great!!!



--
Howard

Please visit my galleries at http://www.pbase.com/howardka

Click to expand...

Click to expand...

--
Howard

Please visit my galleries at http://www.pbase.com/howardka

Bill,

I also hadn't used anything above ISO200 on my A1 after the stories I had heard early on. However having been in Singapore for the past week basically just shooting photos I was in a situation in the tropical Bird Park aviaries where it was either try 400 or don't shoot.

I always shoot in RAW as it gives me a chance to play around later and fine tune, rather than panicking on the spot. Likewise I always suck the shots in via Photoshop CS after Dimage seemed to give less than the best RAW results. Which backs up your suggestions.

To my surprise the ISO 400 shots after a Neat Image pass through were pretty sharp. The remaining noise was minimal and very film grainy, which is perfectly OK with me.

Now to ISO 800...

Somewhere in this thread I read that ACR does not reduce noise. What about the Luminance Smoothing and Color Noise Reduction functions under the Detail tab in ACW. Do other people use this?

Trevis Lawton said:

To my surprise the ISO 400 shots after a Neat Image pass through
were pretty sharp. The remaining noise was minimal and very film
grainy, which is perfectly OK with me.

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Trevis - In my experience, ISO 800 with the A2 has been good if the lighting conditions are good and the image doesn't contain a lot of contrast or a lot of very dark subject matter. In those situations, it's very good indeed. But if I get stuck with a contrasty subject, or if the lighting is really poor, then ISO 800 is only good for prints up to about 4X6 inches.

Here's another thing which is great to do when processing noisy images - maybe everyone else knows this trick. Open your image (preferably a RAW image, opened with luminance smoothing and little or no sharpening - I use ACR but other coverters work too...), do a manual Levels adjustment, then run your noise reduction program - I use Noise Ninja. Now finish processing your image, including any sharpening. Finally, look over the image, if there are areas where you'd like to see less noise, do the following:

Flatten or merge the layers. Make a duplicate layer. Run your noise reduction program again, or run some gaussian blur, on the whole new Background Copy. (Re-running the noise reduction program works a little better, unless the residual noise is really awful - then gaussian blur works best). You can, and probably should "overdo" this somewhat. You'll see why in just a moment.

Now go to Layer/Add Layer Mask/Hide All from the toolbar at the top of your PS screen. Your image should now appear as if you hadn't done that second noise reduction at all.

Be sure your new Background Copy is still selected. Select a brush of your favorite size and hardness, set opacity to about 20%, and paint in** the repeat noise reduction you just did. Be sure you're "painting with white" (the two little squares at the bottom of your left-hand PS tools bar). Now paint. You will see the residual noise disappearing as you paint. You can paint in all your added nosie reduction, or only a part of it, depending on the opacity of the brush you use. Obviously, you can change brush sizes, opacities, and hardnesses if you like. If you've painted in too much noise reduction, you can just hit the "X" key on your keyboard, thus switching to "painting with black", and you can then "paint out" the noise reduction you just painted in. Or by reducing the opacity of the brush you're using, you can "paint out" only part of the added noise reduction. And so forth, back and forth, hitting the "X" key to switch from "painting with white" to "painting with black".

One last thing - if for any reason you want to see only the area where you've painted in additional noise reduction, simply turn off the original Background layer by clicking on the "eye" icon at the left of the (original) background layer in your Layers palette.

This might sound involved, but once you've done it a few times, it will go quickly. This technique can be applied to lots of different processing steps. However, it only** works on a new Copy made immediately after merging or flattening layers.

Bill

Sparky2 said:

Somewhere in this thread I read that ACR does not reduce noise.
What about the Luminance Smoothing and Color Noise Reduction
functions under the Detail tab in ACW. Do other people use this?

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Sparky - ACR is really an excellent noise reduction tool! Often, with ISO 200, you won't even need Noise Ninja or Neat Image after opening in ACR. You're right - it's the Luminance Smoothing which does the job. For ISOs up to 800, you should probably set the color noise reduction in ACR to zero - there just isn't any noticeable color (chroma) noise at those ISOs. But for some ISO 800 images you will want to use some color noise reduction too - maybe quite a lot if it, if there's a lot of dark subject material, or a lot of contrast in the image. Beware of color noise reduction in any noise reducer - it can reduce color saturation and image contrast a lot!

These same warnings apply to Neat Image and Noise Ninja - set color noise reduction to zero, if at all possible. The test which Russell Brown uses is to simply slide the color noise "strength" (in those programs which have that slider) down to zero, up to 100, and back while watching the darker parts of the image carefully. Usually, you won't see one particle of difference at ISO 100 and 200 - sometimes not in 400 either.

BTW - in any of these noise reducers including ACR, it's a good idea to play around with "no sharpening" as you use the tool. It's amazing how much difference that makes. My personal preference in ACR is to allow about half of the default sharpening - amount 30 and radius 0.7 or 0.8 - and then complete sharpening after I've reduced noise and finished post-processing my image. With Noise Ninja, I usually turn off sharpening completely - but each person will develop his or her own perference about that.

Bill