# Canon DSLRs noise reduction better than post-processing softwares?



## IntrepidB (Apr 10, 2014)

I have a question about noise reduction.

Let's say I take a shot at ISO 1600 with an APS-C camera. If I shoot JPEG and use the camera's own noise reduction, how it will compare to shooting RAW and then doing the noise reduction in a software (Lightroom for example)?


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## Overread (Apr 10, 2014)

Honestly noise reduction depends upon the software you use and upon how good you are at using said software. So how good it is depends on how good you are at using the software. 

In general though in-camera has the major weakness that you can't tailour the noise reduction for the image - you also can't restrict the areas of the photo that it affects either. In real world shooting you can easily have photos which have extremes, from areas full of noise to those with significantly less; This makes layer masks in editing software very powerful because you can apply different strengths of noise reduction to different areas - the clean smooth background with no detail can be hit with a much stronger level of noise reduction than the detailed in-focus areas which don't want to be softened from strong noise reduction. 

I would read up on the mechanics of it and learn some methods - in-camera is ok but out of camera is typically capable of a superior result.


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## DarkShadow (Apr 10, 2014)

No its better in post and depending on the software used but for example I can reduce noise in areas that it is more apparent rather then the whole image using aperture.I keep in Camera NR turned off and the lighting optimizer. I have not used any noise reduction for sometime now in camera or in post and I have some ISO shots much higher then 1600 with no noise issue.When you shooting at high ISO it's important to get the exposure correctly in camera and not under exposing it then trying to fix it in post.


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## gsgary (Apr 10, 2014)

Always turn off noise reduction in camera it will make your photos soft


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## KmH (Apr 10, 2014)

Noise reduction is like one side of a coin. The other side of the coin is Sharpening.

As mentioned using in-the-camera noise reduction limits us to applying noise reduction (and/or other editing) equally to the entire photo or what is known as a global edit when what is often needed is a local edit or an edit to just part(s) of the photo.

Note that ACR's (CC/CS Camera Raw/LR Develop module) Sharpening panel is where the Noise Reduction controls are.
Also noted is that noise reduction can have a negative impact on image sharpness.

The small company Pixel Genius, LLC wrote the software that is ACR's Sharpening panel.
The subject of sharpening/noise reduction is involved enough that a member of the company wrote a book:

Real World Image Sharpening with Adobe Photoshop, Camera Raw, and Lightroom (2nd Edition)


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## Derrel (Apr 10, 2014)

IntrepidB said:


> I have a question about noise reduction.
> 
> Let's say I take a shot at ISO 1600 with an APS-C camera. If I shoot JPEG and use the camera's own noise reduction, how it will compare to shooting RAW and then doing the noise reduction in a software (Lightroom for example)?



Honest answer: MANY people can NOT equal the success of the built-in noise reduction software their cameras have when shooting RAW+ JPEG. Many people will see that the camera-created JPEG image looks better than what they can create from a RAW capture.

Camera manufacturers have made better and better and better in-camera software over the last decade. Unless you're pretty skilled, and have good software, I think there's a pretty good chance that shooting RAW+ JPEG might actually create better JPEG images than what you can create yourself later.

Again--it takes software and skill and knowledge to "create" a good JPEG image from a RAW File. Many people do not have enough skill to equal what the camera makers designed your camera to be able to do. On photo forums, there are many people who ARE skilled at noise reduction and JPEG creation...but there are also many people who are not so skilled.


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## Gavjenks (Apr 10, 2014)

My Canons are pretty damn good at noise reduction. I've never found any software available to me that could equal them, or just the RAW converter that shows up by default on photoshop for those images (which is probably an Adobe product mostly, but still somehow does way better than Adobe's photoshop noise reduction filter).

Also, though, I was able to invest a couple thousand bucks in a full frame modern sensor camera and some fast-ish glass, in part so I wouldn't have to worry as often about noise in the first place. It's already like 95% as good as it could possibly be for normally lit shots, so I don't care if some proprietary software could get me to 100%. If you're pushing a M4/3 to 1600 all the time or something like that, then it will be a more persistent problem, and you'd probably notice more of a difference between different noise reductions approaches.


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## SpikeyJohnson (Apr 10, 2014)

I always shoot raw because I love editing. But when I compare the camera sharpening or noise control of my D3200 to RAW and Lightroom or Photoshop, I don't like it.  I think the camera leaves too much noise in for my taste and always want to go back to the RAW file and discard the JPEG (when I shoot RAW + JPEG).


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## jayindhawan (Apr 24, 2014)

Better to turn off the noise in Canon DSLR Camera would be good to take photographs.


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## Trull (Apr 30, 2014)

You could try asking this question in an astronomy forum like stargazers lounge. Every astrophotographer uses high iso and long exp routinely. Raw is the only way forward .


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## Dao (May 1, 2014)

There are time for sure noise reduction is best if do it with software.

i.e.  A bird on a tree branch while background is blur.

If I sharpen the bird, the background may looks noisier or not as good (especially if the bokeh look a little busy - lens characteristic).  So I may need to use 2 layers and sharpen one layer and apply layer mask and then brush off some parts in one layer.  So that the bird look sharp and the background remain good.  (Sometimes I may need to apply a little blur to the background to reduce noise).

If it is just simple noise reduction, I just use LR nowadays.  So far so good.


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## KmH (May 1, 2014)

Trull said:


> You could try asking this question in an astronomy forum like stargazers lounge. Every astrophotographer uses high iso and long exp routinely. Raw is the only way forward .


You didn't mention a lot of them use cameras designed specifically for astrophotography that have a system that cools the image sensor during a long exposure to keep thermal image noise at a minimum.


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## Trull (May 1, 2014)

Yes that's true... But there's a sizable canon population like me using Nebulosity from Stark Labs for awesome results.


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## TCampbell (May 1, 2014)

I've tried several different noise-reduction programs ... and most of them are not impressive.  Adobe... for example... you would think that with all of Adobe's photo-wizardry that they'd actually be good at noise reduction.  But I find it mostly unimpressive.

The best tool I've found to date is Imagenomic's Noiseware (available as a standalone program or as a plug-in to Photoshop or Aperture.) 

What I like about it is that you can completely "tune" the noise characteristics and aggressiveness.  You tend to get low noise in highlights and heavy noise is shadows, but you can can tune this by the level of noise, level of correction based on range or frequency, and you can also tune it for chroma vs. luma noise, etc.  

Noise reduction tends to soften an image... and image sharpening tends to drive up noise.  They compete.  

A nice happy way to deal with this is to apply the noise reduction (which smoothers the whole image) but rather than applying a general sharpening, you can apply "edge" sharpening.  That tool specifically seeks out pixels that form a high contrast edge and applies sharpening only along the edge -- ignoring the non-contrasty area (if you tried to sharpen those areas, you'd just generate more noise.)


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## TCampbell (May 1, 2014)

KmH said:


> Trull said:
> 
> 
> > You could try asking this question in an astronomy forum like stargazers lounge. Every astrophotographer uses high iso and long exp routinely. Raw is the only way forward .
> ...



Astrophotographers shoot "bias" frames (and astro-imaging CCD cameras actually have a bias generator).  A "bias" frame is basically a 0 second exposure.  This is generated to find the "floor" in the image data.  This is because the sensor can't work without power.  If you don't apply a charge, you can't read-out any data from the chip.  We want to figure out how much signal is naturally present in the image just because the camera sensor was operating.  That comes out of the bias frames.  With a DSLR you take the shortest exposure possible with the lens cap on.

And then there are the "dark" frames.   Astrophotographers shoot "dark" frames (exposures taken in the same conditions as the "light" image in that the ISO and exposure match and also the physical temperature of the camera and ambient temp matches... but the camera is covered), which like the bias frames, have the lens cover on.  But these are long in duration so the sensor can build up noise.  We're looking for random noise and pattern noise.

We also shoot "flat" frames.  These are frames with the camera open to light... but shooting into a flat white light source which must be evenly illuminated.  The purpose of this is to detect natural lens vignetting.  Straight out of the camera, vin getting may not be strong enough to be noticeable.  But most of the data in an astrophoto is on the left.  The image has to be "stretched" to bring out the details and when you do this you REALLY exaggerate the effect of lens vignetting (so vignetting that was barely even noticeable becomes extreme.  The "flat" frames are designed to remove all effects of vignetting.  It also gets rid of dust bunnies.

And then there are the "light" frames.  But we don't just shoot one... we shoot lots of them and there are some tricks.  The REASON we shoot lots of them is, in part, to combat the noise problem.  

A lot of noise will be random.  So if I shoot a lot of images, the very tiny points of light that really are stars will consistently be visible in every frame.  The points of light that are actually noise will be random in every frame.  By doing alignment and "registration" of the frames, we can determine which points are really stars and which points are really noise and eliminate the noise.  But how well this works depends on how many frames you shoot.  Your ability to combat noise is a Poisson progression -- the noise reduction can be improved by the square root of the number of frames you shoot.  Shoot 4 frames and you can double the effectiveness of noise reduction.  Shoot 9 and you can triple it.  Shoot 25 and you can make it 5 times better.  Usually more than 25 and you get to diminishing returns.

But then there's "pattern" noise.  Pattern noise will appear somewhat consistently in the same spot and in every frame which means that even with all of our techniques they might be mistaken for stars.  To detect it, we can use the dark frames.  But we can also use a technique called "dithering" with the telescope mount.  Dithering means that the position of the telescope moves very slightly between each frame.  The auto-guider camera and image acquisition software both talk to each other.  When the camera finishes one frame, the image acquisition software notifies the auto-guiding software... which then moves the telescope amount by a tiny amount... really just a few pixels.  When the mount is settled, the guider software notifies the image acquisition software that it's ready to take another frame and the two keep doing that for hours until all the frames are captured.  Since each frame is just barely offset, any real stars will have shifted, but the pattern noise will remain in place.  Since the image registration process (the stacking process) will use stars to "register" the alignment of the images, this pattern noise will now appear in different places in each frame and that makes it easily detectable by the computer so that it can be eliminated.

And all of this (combined with those cooled sensors) is just to capture the data and integrate it.  This all allows the computer to do a much better job cleaning up all the noise in the frames.  

But it doesn't end there... when we process the image, there are a number of things we can do to to clean up the image based on a variation of the zone system.  It's like the Ansel Adams zone system, but with just four zones.  The zones are basically the dark, dim, medium, and light zones.  Everything is based on the theory of how to deal with the "signal to noise ratio".  In a "dark" zone there is almost no data (extremely low signal) but some level of noise.  The noise is stronger than the signal.  Since there is very little useful data, that zone can simply be sent to black and eliminated.  Noise in that zone is gone... because everything in that zone is now gone.  In the "dark" zone, the SNR is not great... but you don't want to just wipe out the data because there's some useful data there.  Instead... you apply aggressive smoothing in that zone but absolutely no sharpening.   In the middle zone you can apply a tiny amount of sharpening and de-noising... but not too aggressive.  In the light zone you probably won't need to de-noise it and you can be very aggressive with the sharpening.   (BTW, this is basically what Noiseware is doing with it's tunable noise reduction based on zones.)

You can imagine how, with all of this (and this takes years of work to master) that even a noisy camera might actually produce astro images with good results (of course you get even better results if you start with low-noise data from a better camera.)

The guys that have mastered this turn out images that look like they were taken by professional observatories or space telescopes... the image quality is staggering.


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## Trull (May 1, 2014)

Indeed... If you fancy some inspiration then check my mate's site www.philhart.com he uses 20D, 450D, 5DII... Also a CCD...


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