Using sharpening/noise reduction in Raw

[AdrenoJunkie]

Can anyone explain to me, in dumbed down terms, how to use sharpening and noise reduction in ACR? Other than the amount slider, I don't understand any of the other sliders and can't tell what effect they have.

[LeeR]

Enlarge your image to at least 100%; preferably to an area with some detail. Then press and hold down the ALT key while using the slider. The scene will turn black and white and you will be able to see the effect of what you are doing. (This won't work if your image is less that 100%) The first slider is the amount of sharpening; more for detail work, less for portraits. The second is radius, that is how subtle the sharpening ramp is; 0 for no ramp, 3 for a very subtle 3 pixel ramp up to the ed. The next slider is Details; again more where you want lots of sharp details, less for portraits and a softer effect.
Finally there is the masking slider. This one is amazing. I am always telling people about using edge masking so you are only sharpening the edges and leaving the middle areas soft. This allows you to use more sharpening because you are only using it where you need it. Again, press and hold the ALT key and as you slide to the left you will see the program create an ever tightening mask around the edges. Stop where you want the sharpening applied.
The last two sliders are for noise reduction. The ALT key trick doesn't work here, so I usually enlarge to 200 or even 300% and watch what effect the sliders have on the noisy areas (usually large flat dark areas.) The first is for luminance noise, the most common kind and if that doesn't clear things up and you have a color image, you may try the color noise reduction. I'm not realy impressed with the program's noise reduction; there are programs out there that do a much better job. However, the sharpening, and especially the masking, are incredible.

[plyingsaucer]

I think i just earned a couple of experience points from this thread. Thanks for asking Adreno and thanks for answering Leer. Everything suddenly made perfect sense. Cheers!

[RecurrentNerve]

Great answer LeeR

[OsmosisStudios]

I would actually advise not using the sharpening in ACR. The noise reduction works well, but the sharpening is best done in Photoshop proper using a highpass filter.

[LeeR]

Originally Posted by OsmosisStudios

I would actually advise not using the sharpening in ACR. The noise reduction works well, but the sharpening is best done in Photoshop proper using a highpass filter.

I am a huge fan of High Pass Sharpening; I used it exclusively for years and still do for most portrait work. However, two things have encouraged me to branch out a bit. The first was the concept of edge sharpening with a layer mask which allows you to specify exactly where you want sharpening. The second was the desire to do everything I could in ACR. No doubt you can accomplish everything in PS that you can in ACR and may even be able to take it farther, but if your image only needs modest sharpening the tools in ACR are quick and adequate. Plus, being able to save these settings and apply them to multiple images in Bridge or Lightroom is another huge advantage. Lastly, all of the adjustments in ACR are parametric, which means you can go back and rework them any time you want with no loss of quality. Strong reasons to at least be aware of these tools and what they can do for you.