How to reduce noise in RAW with k20d

lawjbm · 10-27-2009, 09:39 PM

Hi:

I hope this is the correct forum in which to ask this question.

With all of the recent postings about how the kx has superior high ISO performance compared to the k7 (and k20d) I also believe I have read a number of people state that in RAW they can further reduce noise as compared to shooting JPEG.

I generally shoot RAW and process in ACR using CS4. I have held off buying noise reduction software, though I may take the plunge. I generally shoot at 100 or 200 ISO in my home studio. Lately, though, as I have shot a bit more on location, I find myself not always able to light as I want and having to go to ISO 800. If my exposure is off and I need to add exposure compensation or fill light then I can end up getting a fair amount of noise that even (the trial version of) Noiseware has to smooth a lot before no longer being objectionable--and then I lose some needed detail.

Is there a way in RAW--other than using RAW's noise reduction--to minimize noise, especially when adding fill or exposure compensation?

Thanx so much for your help.

Gregg

kittykat46 · 10-27-2009, 10:13 PM

Adding exposure compensation in PP is definitely going to increase the noise, even in RAW. That sort of noise is more difficult to clean up, and you have to accept some loss of detail cleaning up such photos. The good thing is, with a 14MP shot, you may still have a very usable picture to view full screen or print out A4, though the loss of detail will be obvious for 100% crops.

You really need a correctly exposed photo to start with

Anyway, most decent RAW development software have usable Noise Reduction.
I use Silkypix 3.0 , which has reasonably good NR, unless it is an exceptionally noisy shot.
You mentioned you would go up to ISO800 at most - the very minor amount of noise there should clean up very nicely without being too aggressive with the NR.

Specialised NR software like Noiseware and Noise Ninja are very good.
I've tried Noiseware - its almost unbelievable the way it cleans up both Chroma and Luminance noise.

lawjbm · 10-27-2009, 11:30 PM

Kittykat:

Thanx so much. I guess I was hoping I had missed something.

I appreciate your reply.

Gregg

*Ash* · 10-27-2009, 11:48 PM

ACR's noise reduction is not all that effective IMO.
I resort to leaving ACR's NR settings defaulted for each of my shots and after all PP editing on Photoshop, leave noise reduction and sharpening to last by Photoshop, both of which works much better for me.

Just depends what PP program you use and if you find it's NR feature good enough for you.

CrazyNuts · 10-28-2009, 02:18 AM

For those of you who don't know, there is a free version of NoiseWare

http://www.imagenomic.com/setup/2007...etupXP2601.exe

This is direct from the developer.

ozlizard · 10-28-2009, 04:20 AM

Will check out that freebie, thanks for the link. I have been taking some long exposures with an ND8 filter (30sec or less) and noticed a lot of noise in the resulting images. I don't think the NR in the K20 is very good or maybe it's just me?

*dadipentak* · 10-28-2009, 08:37 AM

Originally Posted by Ash

ACR's noise reduction is not all that effective IMO.
I resort to leaving ACR's NR settings defaulted for each of my shots and after all PP editing on Photoshop, leave noise reduction and sharpening to last by Photoshop, both of which works much better for me.

Helpful comment, Ash--I just discovered ACR's NR and sharpening features

and it struck me that it was the the wrong end of the process for such things so I just cranked them down as low as they would go.

lol101 · 10-28-2009, 09:03 AM

Originally Posted by dadipentak

Helpful comment, Ash--I just discovered ACR's NR and sharpening features and it struck me that it was the the wrong end of the process for such things so I just cranked them down as low as they would go.

I may be wrong but I think that begining the PP by NR is actually the best way to do it.

I thought NR worked best on "raw" noise which is (should be?) uncorelated as long as you didn't edit the image?

Furthermore, you can apply NR selectively in LightRoom (CS4 should work the same?) which often comes in handy IMO.

robgo2 · 10-28-2009, 12:09 PM

Originally Posted by lol101

I may be wrong but I think that begining the PP by NR is actually the best way to do it.

I thought NR worked best on "raw" noise which is (should be?) uncorelated as long as you didn't edit the image?

Furthermore, you can apply NR selectively in LightRoom (CS4 should work the same?) which often comes in handy IMO.

Here is my take on NR:

ACR/LR is very poor at reducing noise, and I never use it. DxO Optics Pro is the only RAW converter that, to my knowledge, removes noise prior to demosaicisation, which is far superior to doing so afterwards. Still, it does not always remove all objectionable noise.

Of the post-conversion NR software that I have used and tested, I find Dfine to be the best. It seems to remove noise mainly where it exists, while leaving non-noisey areas unaffected . Also, Dfine allows very localized application of NR, so that you don't have to treat the whole image uniformly.

Hope that this helps.

Rob

*tcdk* · 10-28-2009, 01:14 PM

The new LightRoom 3 Beta should have better should have better NR. May be worth a try...

*Ash* · 10-28-2009, 01:30 PM

Originally Posted by robgo2

Here is my take on NR: DxO Optics Pro is the only RAW converter that, to my knowledge, removes noise prior to demosaicisation, which is far superior to doing so afterwards.
Rob

Originally Posted by dadipentak

I just discovered ACR's NR and sharpening features and it struck me that it was the the wrong end of the process for such things so I just cranked them down as low as they would go.

Rob, you may be right and dadipentax I may be wrong with when NR should best be performed. There's no proof to my reasoning, but I do notice that at times in my own PP process noise seems to be amplified and so I leave NR to the end to try and smoothen that out.

If done first, I may be left with residual noise that is then amplified in the same way in my PP process - but this logic may be flawed.

*dadipentak* · 10-28-2009, 03:21 PM

Originally Posted by Ash

Rob, you may be right and dadipentax I may be wrong with when NR should best be performed. There's no proof to my reasoning, but I do notice that at times in my own PP process noise seems to be amplified and so I leave NR to the end to try and smoothen that out.

If done first, I may be left with residual noise that is then amplified in the same way in my PP process - but this logic may be flawed.

I'm following this exchange intently. I certainly have understood that sharpening should be done last but typically have done NR (with Neat Image) after RAW conversion but before cropping and sharpening.

lawjbm · 10-28-2009, 04:18 PM

Hi all:

I want to thank everyone for your suggestions.

At the risk of sounding cliche, let me also say, I am very grateful for all of the help I have received on this forum since I bought my k20d. It is amazing that people all around the world take the time to provide such quick and helpful responses. I will never meet most, perhaps all of you, but I really do appreciate the time and information you have provided to me.

I will take another look at buying Noiseware or Dfine. It was not a financial issue--these are pretty reasonably priced programs. I just had kept things at 100 or 200 ISO. Now that I am becoming more serious and going on location I cannot always light like I want to and have to punch up the ISO.

I guess I thought (hoped) that RAW might help me save an underexposed photo. I know it gives me more leeway than JPEG, but I am learning there are limits.

Thanx again.

Gregg

**Marc Sabatella** · 10-29-2009, 10:30 AM

My assumption has always been that it is better to do NR in RAW than post conversion. That is based on the logic that it's really actually about signal-to-noise ratio and getitng that as high as possible, and the way to do that would be to be sure to start with as much signal as possible - and that means the original, un-demosaiced, 12-bit (or whatever) RAW sensor data. Anything after that - even demosaicing to 16-bit TIFF - seems like your starting off with less real signal.

FruitLooPs · 10-29-2009, 06:41 PM

Originally Posted by CrazyNuts

For those of you who don't know, there is a free version of NoiseWare

http://www.imagenomic.com/setup/2007...etupXP2601.exe

This is direct from the developer.

I just tried it on a nice wedding shot I had that was underexposed quite a bit, wow what a difference! cheers