Noise reduction

richardsmith · 10-25-2009, 09:16 AM

I have a K-2000 and find it very noisy at ISO 1600. It has options for noise reduction for long exposure and also for high ISO but they don't seem to have much effect. I'm shooting RAW. Are they supposed to work for RAW or only for JPEG?

If I'm going to be removing noise later with Noise Ninja, is it better to turn off the noise reduction in the camera?

Has anyone used the 'auto noise compensation' option in Apple Aperture's RAW processor? It has absolutely no effect for me whatsoever, so I wonder if it's only supported for certain RAW formats.

**Marc Sabatella** · 10-25-2009, 09:55 AM

The high ISO NR is only for JPEG. The slow shutter NR works for both JPEG and RAW, but only for truly long exposures - measured in seconds, not fractions of seconds. You'll know it has kicked in because it will take as long for the camera to be ready to take another picture as the exposure itself - a 10 second exposure takes an additional 10 seconds for the slow shutter NR to occur (because it works by taking a second image with the same shutter speed but shutter closed and comparing).

I find with my K200D - same sensor as your K2000 - that there is quite a bit of "chroma" noise (colored specks), but luckily, this is very easily removed in PP without having much effect on IQ at all. On my high ISO images, I turn the chroma NR up all the way and the colored specks pretty much disappear with almost no loss of detail. Then I apply just a *touch* of luminance NR, since that is what kills detail. I have this saved as a preset, so in seconds, I can clean up as many images as I want without leaving the RAW domain. I'd only resort to a program like Noise Ninja in an extreme emergency, since as far as I know it requires you to leave the RAW domain in order to work, thus breaking up the workflow far too much for me to want to go there.

BTW, since high ISO NR does not affect RAW, it doesn't matter how you set it. but if you are doing long exposures, then you really do want that slow shutter NR, because the method it uses ("dark frame subtraction" - taking that secnd picture with the shutter closed) can't be emulated by Noise Ninja.

richardsmith · 10-25-2009, 11:27 AM

Thanks, that is very useful.

You are right that Noise Ninja forces conversion to TIFF. The Noise Ninja documentation actually recommends running it *before* you do any other processing, but I don't want to give up the flexibility of RAW so I just run the images through Noise Ninja as the last step at the end of the workflow.

Aperture has a built in noise reduction tool but it's not as good as Noise Ninja. Shame they can't integrate the Noise Ninja algorithm. Bibble does this apparently and lets you run the Noise Ninja on the RAW, but Bibble doesn't support K2000 RAW format properly. I haven't tried Lightroom yet.

*tcdk* · 10-25-2009, 04:21 PM

If you try Lightroom, you should look for the just released LR3 beta. It should have better NR then LR2...

mysticcowboy · 10-26-2009, 07:01 PM

Originally Posted by tcdk

If you try Lightroom, you should look for the just released LR3 beta. It should have better NR then LR2...

Adobe hasn't turned on all the options for NR in the beta, so it's not an option yet. However, NoiseNinja does offer an Aperture plugin. Haven't tried it, but have used the DeNoise plugin with good results.

michael mckee
My Port Townsend – A City in Photographs