When to do noise reduction and sharpening?

[iamjediknight]

I use Lightroom and Photoshop am wondering when to do noise reduction. Would I do it in Lightroom before making adjustments? Right before I take the photo into Photoshop? Or after I return from Photoshop?

Thanks, Scott.

[stephenpinn]

I was taught before on the noise reduction and after on sharpening, as sharpening is dependent on your target output format

[venchka]

I do it when I feel like doing it in Lightroom. Photoshop not available.

[JohnT]

I've always done NR prior to sharpening based on articles and books that I've read. If you sharpen first, more aggressive NR will be required and will negatively affect your sharpening. However, if you NR first, then you can sharpen without reintroducing too much noise back into the image.

[Tom]

Do all your edits. Then NR and Sharpen based on output before exporting.

[JohnT]

Let me add that the LR sharpening algorithms are based on those of PixelGenius' PhotoKit Sharpener program so it's a great way to sharpen images.

[Donb10]

I'm no expert but I have been playing with Photoshop for a good while. However, everything I have learned and applied to my post processing has come from forums like this one.

First, I think most people do their sharpening at the end of their processing. When it comes to noise reduction, I do mine as the first step after converting my raw files and opening them in Photoshop. I then open a levels adjustment layer and check all six colors using the histogram. Depending on the photo I may make additional adjusts but my last process is sharpening.

For noise reduction, I use Topaz Denoise 5. Being retired, I have some spare time so this morning I played with several images that were taken at ISO 6400 with a canon 7D. Both images were taken with available light. Both were shot in RAW then opened in Photoshop. I processed both images using the same adjustments (when possible) and used the Denoise plugin as a first step and then processed them again using it as a final step before sharpening. I used the default settings by Topaz (RAW Stronger) each time and the default settings using the Denoise software at the start of the post processing were much less than when it was applied after adjustments. When viewed at 100% the photos where the noise reduction was applied first were considerably cleaner than when it was applied later.

Nothing scientific about my little test but for me it shows that the noise in my photos using Topaz Denoise was reduced more as a first step in post processing. It might be different with other software.

[iamjediknight]

Thanks John and Don! You really helped me out.

cheers, scott.

[JohnT]

You're welcome, Scott. Happy to help.

[rbalcom]

Originally Posted by Donb10

I then open a levels adjustment layer and check all six colors using the histogram.

When you check the six colors, what are you looking for and what do you adjust to accomplish?

[Donb10]

When you open the levels adjustment layer there is a histogram shown. The channel box by default is set to RGB. If you click on the black down arrow, it shows the Red, Green, and blue channels. Each of them have their own histogram. If you open the red channel, the left side of the histogram (black slider) is actually an adjustment for cyan and the right side (white slider) is the adjustment for red. Sometimes there is a gap on one side or both where you can move the sliders to the correct point on the histogram.

You can hold down the Alt key and then click and hold down the mouse key on either of the sliders and your screen will change to a solid color. Then move them slowly in towards the center. When you start to see black spots on the color screen it usually a good point to stop, release the mouse and look at the photo.

The left side of the Green channel is magenta and the left side of the blue channel is yellow. If you want to see how they change, open the red channel, click on the black slider and drag it towards the center.

Some people just adjust the histogram sliders with the channel box set to the default setting of RGB. However, in doing this, you may be adjusting a color that does not need adjusting.

I hope this answers your question, sometimes its hard to explain these things on a keyboard.........

[Bob_S]

If you are using a tool outside of LR or PS, meaning something will alter and save the file, then load it back into LR or PS then you want to do NR first before sharpening makes the noise worse.

I don't believe it really matters if you do both NR and sharpening in LR. At least on a 2:1 crop, it looks the same no matte which order you do it.

[rbalcom]

Thanks, Don.

It sure does answer my question. I will have to play with it a little to really understand it, but I appreciate the help.

[Charles Putnam]

Couple of thoughts. If you shoot in RAW (and you should), the Camera RAW plug-in provides noise reduction capabilities. FWIW, the PS CS5 version is vastly improved over CS4 in that...it actually works.

Beyond that, I've used both Topaz DeNoise and Neat Image. Both are excellent. However, I've found that DeNoise takes a LONG time to process vs. Neat Image.

Where to check for noise - shadow areas. Check there first to see if there is any measurable/visible noise first.

As to sharpening, I do some sharpening in Camera RAW, but usually leave that as the last step.

I'm in the process of redoing my workflow by using Aperture 3 first. Aperture 3 has some excellent noise and sharpening tools built in. The goal is to do the bulk of the processing in Aperture 3, and any fine-grained work that's necessary in Photoshop.