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Tannin
29-11-2008, 3:03pm
In a PM just now, an AP member asked me for some tips on using Neat Image. I thought it would make more sense to post the answer here so that everyone can read it, and other members can add their own tips and tricks. I am not by any means an expert at using Neat Image, nor at post-processing more generally, but I've been using it for quite a while and have developed some methods that work fairly well.

For wildlife work with long lenses, you nearly always wind up using a higher ISO than you would ideally want. Most experienced bird photgraphers routinely work at ISO 400 and will readily go to ISO 800 if needed, and then, depending on the camera model and the circumstances, higher again if they have to. Most of my 1D III shots are at ISO 500 or 640; 400 if I can, 1600 more often than I like, 3200 if I'm desperate. On any camera, the luxury of shooting at ISO 200 is a rare one.

Noise reduction should be regarded as an integral part of the photographic process, certainly once you go past ISO 200. Think of running Neat Image the same way you think of cropping, adjusting levels, sharpening, and so on - it's just part of what you do with every image. I believe it is much better to turn all in-camera noise reduction OFF - your computer is vastly more powerful than any camera logic, can run much more sophisticated software, and above all, can do it in different ways for different images - this puts you in charge and let's you process each image in the best way rather than be stuck with the irreversable one-size-fits-all of in-camera noise reduction.

Tannin
29-11-2008, 3:04pm
A fundamental rule of noise reduction is that you do it before you sharpen. Otherwise, you accentuate the noise and then have to blur all the detail out with excessive NR.

Reduce noise early
Sharpen late
Do all the other things as you please.


Let's start at the point where we have a visible image: i.e., either an out-of-camera JPG or the output from our raw converter. Mostly, I use the JPG though I nearly always shoot in raw +JPG just in case.

While you nearly always reduce noise before you sharpen, it often doesn't much matter at what stage you do many of the other adjustments. Levels then Neat Image? Or Neat Image first? Sometimes I do one, sometimes the other. In most cases it doesn't seem to matter. Most often, I will do something like:

Levels
Tweak colour balance if desired
Neat Image (generally but not always including input sharpening)
Area-specific changes (dodge and burn, selective sharpening, selective contrast adjustments, clone out dust - whatever)
Crop
Adjust saturation, possibly make final adjustments to exposure
Save master copy
Resize
Output sharpening
Save display copy


(Actually, I use a PMView (http://pmview.com) macro to do those last three steps about five times to create, sharpen, and save to appropriate folders versions in 800px for the web, 1024 x 768 for the data projector, 1280 x 1024 for standard screens, 1600 x 1200 for high-res screens, and 1680 x 1050 for when I'm forced to use the laptop screen. Takes a couple of mouse clicks to do the whole lot.)

Back to the sequence above: the main thing is to do the noise reduction before you do the output sharpening. Al the rest of it is fungible.

Tannin
29-11-2008, 3:08pm
Now, Neat Image itself. First, we set some defaults.

Set the output file type to TIFF, and set it to use a sensible file naming convention. It defaults to xxxfiltered (where "xxx" is our original file name. Change that to xxxf or something else short and easy to remember.

I like to use Neat Image to do input sharpening as well as noise reduction. You can see that setting here in the screenshot at lower left:

http://tannin.net.au/other/ap/neat/options.jpg

This will give us a mild sharpen over the whole image: something you will barely see, but which produces a nice result later on after we have cropped, resized, and done our output sharpening. But you have to check every time! More on this shortly.

For the noise reduction settings, let Neat Image do an auto-profile and an auto fine-tune (not sure that the fine tune ever does anything much, but I let it run anyway), and leave everything else at the factory default settings - amount of noise reduction, and so on. The factory defaults were selected by people who know far more about noise reduction than you or I ever will and are usually pretty good.

Let's flip to the preview screen and take the zoom up to 100%. Don't look at the noise, look at the subject! Make sure that the noise reduction has not smeared away the detail. Move the preview square around to check in different places, and to familiarise yourself with the differences between the filtered and unfiltered versions. If you are happy, commit those changes and go on with the rest of your PP.

But what if it doesn't look right? Some images look much worse after NR and input sharpening! First, switch off the sharpening and preview again. Experience will help you judge whether an image looks worse instead of better because it can't take sharpening, or because the noise reduction is smearing all the detail away. Next, if you are still not happy, reduce the noise reduction amounts:

http://tannin.net.au/other/ap/neat/amounts.jpg

Here you can see that I've taken the high frequency noise reduction down to 50% and the medium frequency to 70%, but left the low frequency at 100%. That's a pretty good first guess for when you are losing too much detail or getting that smeared plastic look. You will soon discover that the low frequency is never a problem., always the high and medium. Just keep adjusting them down until you are happy with the result. Flip the sharpening back on again and decide if you want it or not. (You can adjust sharpening amounts too, but by the time you get to this stage you are getting pretty fussy and might do better to use unsharp mask or Smart Sharpen instead.) Infrequently, you will decide that no noise reduction setting is very useful and either discard the image or decide to simply live with the noise. Mostly, though, Neat Image will give your shot a nice lift and you can go on with the rest of your workflow.

I @ M
18-12-2008, 6:58am
Thanks for this one Tony, folowed the link from your Ver 6 available post and have been having a play with the free download trial version.
After a quick play with some unedited files here, comparing it to the noise reduction system in Nikon Capture NX2 it has some definite advantages with the way it deals with noise.
The only drawback is that it can't be selectively applied to one particular area of the image as can be done in NX and of course the free version only allows the output to be saved as a JPEG with compression applied.

Seesee
18-12-2008, 1:10pm
I bought the pro version of neat image and it's quite good, but I haven't really sat down to experiment fully yet, haven't really experimented with using it for sharpening yet, but sounds like I should do so.

IanB
18-12-2008, 2:03pm
That's what I like about this site>members more then willing to give up their time to help the less experienced members>excellent thread Tannin>thank you; it's something I did not know .:th3:

jim
19-12-2008, 1:05am
Might mention that if you use Neat Image as a Photoshop plugin (no use to you I know, Andrew) you can use PS to select parts of the image and apply Neat Image as a filter selectively. If you have a noisy oof background in several colours you can cover it incrementally by just repeating the last filter in PS.