Thursday, April 10, 2014

Shooting in RAW: Noise Reduction

More Reasons Why Shooting in RAW is Good

Noise.  Every photographer’s worst enemy.  It’s that grainy look in a picture when it’s too dark to get a good shot and your camera compensates for the darkness up to its limits.  Usually it happens when you are taking a picture indoors and to the eye it seems like there is enough light.  But your camera says otherwise.  Maybe you’re too far away to use your flash.  Maybe the flash would ruin the shot you are going for and so you adjust your camera settings to shoot in low light.  Up until recently I shot with a Canon T2i, so that meant setting my ISO to 3200 and praying.  I think the camera could handle up to 6400 ISO, but that was just asking for trouble.  My pictures always turned out to grainy even at 3200.  Now I shoot with a Canon 6D and I sometimes flirt with 10,000 ISO and the picture comes out fine.  Cameras are more than just the number of megapixels.  So what do you do if your best shots come out too noisy (grainy)?  Good thing you’ve learned and are shooting in RAW.  You can still adjust for noise with a JPEG, but as with everything else, I think the adjustments come out better in RAW processing.

The Details
                                                                                                                 
If you are working in Photoshop Elements, like me, then here is a picture of the settings that we are discussing (circled in red).  Other programs will have similar settings.  Looking at the picture below, you’ll see at the top that we’ve switched from the shutter icon on the left (where most of the RAW adjustments are) to that triangle-looking icon.  This gives you access to Sharpening and Noise Reduction.




How it Works

There are two types of noise.  Luminance noise is that grainy look that we’ve been discussing.  Color noise is a purple/green outline around certain objects in your picture.  Color noise happens most often when using low quality lenses.  While the adjustments in the diagram above help combat color noise too, I’m focusing mainly on luminance noise here.  To reduce the graininess of your picture, move the Luminance sliders to the right.  

The pictures below give you an idea of how it works.  The first is a shot taken with my Canon T2i at 3200 ISO, so it’s pretty grainy.  It might be difficult to see with this example, but trust me, if you zoomed in you would definitely see a lot of noise.



Compare that to this next picture where I adjusted the Luminance slider in the noise reduction area.  You should see that the graininess that was all over the helicopter is mostly gone.




What You Give Up

It might be difficult to tell unless you zoom in on the second picture but the result of using the noise reduction is a loss of detail.  Compare the two pictures by looking at the guy sticking his head out the window near the front of the helicopter.  The noise reduction tool makes your picture a bit blurry…especially if you use too much.  This makes sense because the tool is getting rid of that fine detail that makes up those specks of noise.  It blurs them out so to speak.  But you also get a blurry picture as a result.  So the lesson here is don’t go crazy with the Noise Reduction Tool.  A little bit is OK, but if your picture is too grainy, it might just be a lost cause. 

Caution

You have probably picked up on the fact that the Noise Reduction Tool is purposefully placed in the same area as the Sharpening tool.  Sharpening is definitely a good idea when you reduce noise as a way to try to get some of that lost detail back.  However, what usually ends up happening is that people over-sharpen way too much as they try to recoup all of the lost detail.  Too much sharpening looks bad.  Just come to terms with the fact that some of the detail will be irretrievable when you do a lot of noise reduction.

Wrap Up

I have discussed what causes noise in a picture as well as how to compensate for it using Photoshop Elements in the RAW editor.  I have discussed the drawbacks of using noise reduction.  There are other aspects to noise reduction that you can research on your own if you wish.  For example, some cameras, such as my Canon 6D, can automatically do some noise reduction within the camera itself when the picture is taken.  Also, there are separate editing programs that focus only on noise reduction.  Some people swear by programs such as Noise Ninja and others.  I have not used these programs and so I cannot comment on how well they work. 

Next Week: Applying saturation to specific colors

Do you have any success or horror stories?  Feel free to post your comments and questions to this post and I’ll be happy to discuss them.  Happy shooting!


Bryan Rasmussen owns Chiseled Light Photography and is also a freelance photographer for a local newspaper. Follow him at www.facebook.com/ChiseledLight. He is also on Instagram, Flickr, and Fine Art America.

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