Effective noise reduction - How do you do it?

Hi All,
I have always struggled a bit with noise reduction - It seems like guess work to me!
Last night I was shooting a school nativity, and while I arranged with the school for the main shoot to be at the dressed rehearsal where I could move around freely, I still took some shots "On the night" to make sure everything was covered, including the proud parents etc.

Now just to set the scene a little, the play was in York Minster, a huge cathedral (Which are never brightly lit) and it was also at night. This left me with some shots being taken with ISO up as high as 6400 - Those with D4's etc will see no problem with this, but I have a D7100 and I treat ISO3000 as my limit as I find noise reduction pretty baffling. The rehearsal was still in the Minster, but during the day & with the lights a little higher.

Obviously I can't post shots of the school play, but here is a shot I took when I arrived to see how the light was....



This shot has no sharpening or noise reduction (In camera NR was set to "High")


My question is how do you go about sharpening and reducing noise while maintaining a reasonable level of detail? The shots I have of some of the audience are a problem, as they were in very bad light, and when I do noise reduction on them, they end up looking like they are wax works! I use either LR or Nik Tools' DFine to do the reduction, and get very mixed results.


Here's a link to the RAW file for the shot above, if anyone wants to play - https://www.dropbox.com/s/v8e1uycne7gml2z/DSC_7079.NEF?dl=0

The most important thing I do is up the exposure compensation when shooting higher ISO. If needed I rather up the ISO even more to be able to overexpose.

I check the shot only for noise that really affects the shot. If the noise doesn't do any harm, I ignore it. If I can't get a good result with the overall noise reduction, I use brushes to try and adjust it locally. I either use noise reduction or blur to brush over the parts requiring such and sharpen what is needed.



I only used LR for this. There's still noise but if I push it more, the curtain starts to fade out. I used 35 luminance noise and 65 sharpening with a mask. I also upped the saturation in the blue channel of camera calibration. I'm pretty sure with people in it, things would get very hard.

Maybe someone can get more out of it in PS.

J-see said:

The most important thing I do is up the exposure compensation when shooting higher ISO. If needed I rather up the ISO even more to be able to overexpose.

I check the shot only for noise that really affects the shot. If the noise doesn't do any harm, I ignore it. If I can't get a good result with the overall noise reduction, I use brushes to try and adjust it locally. I either use noise reduction or blur to brush over the parts requiring such and sharpen what is needed.

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Cheers J-See, that sounds like a good technique! The majority of shots are fine with a little grain, and I could adjust faces with a brush individually.

SteveH said:

Cheers J-See, that sounds like a good technique! The majority of shots are fine with a little grain, and I could adjust faces with a brush individually.

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The only downside besides being a lot of work is that noise is about the most system demanding task in LR. When brushing noise and sharpening, my cooling sounds like a rocket engine. If that becomes a problem, it helps when saving the shot as a TIFF in between and continue processing those.

To add why I tweak the blue channel in cam calibration.

Some will say that adjusting the saturation in the blue channel (which contains most noise) will make things worse but in my experience it does help. While it doesn't necessarily gets rid of noise, it makes the colors over-pop noise and in that, it becomes less distracting.

Here's a shot with a normal blue channel and a second where I upped the blue saturation to the max. It's 100% so that always looks worst. In the full shot, the effect works best.





For many shots adjusting the blue channel does very little harm color-wise and it can help a bit with noise.

Yeah I can see the shots of the audience with 15-20 faces being a pain, but then, I'll see how it goes!

J-see said:

To add why I tweak the blue channel in cam calibration.

Some will say that adjusting the saturation in the blue channel (which contains most noise) will make things worse but in my experience it does help. While it doesn't necessarily gets rid of noise, it makes the colors over-pop noise and in that, it becomes less distracting.

Here's a shot with a normal blue channel and a second where I upped the blue saturation to the max. It's 100% so that always looks worst. In the full shot, the effect works best.

View attachment 126920

View attachment 126921

For many shots adjusting the blue channel does very little harm color-wise and it can help a bit with noise.

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That does look better - I hadn't heard about the blue channel linked to noise - Another good tip! Thanks!

Blue is noisiest followed by Red. Green is the cleanest channel. It's a cost-related side-effect we endure.

I don't know if you can lower noise per channel in PS these days but if, it would be best to reduce it only in the Blue, or Red if really needed, and leave the Green alone.

J-see said:

Blue is noisiest followed by Red. Green is the cleanest channel. It's a cost-related side-effect we endure.

I don't know if you can lower noise per channel in PS these days but if, it would be best to reduce it only in the Blue, or Red if really needed, and leave the Green alone.

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I would be interested to know with elements 11

mikew said:

I would be interested to know with elements 11

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I can't de-noise each channel but if you can, give it a try and tell me how it works.

It's also very obvious in night shots that the three channels are not equally distributed. If I gather light, I occasionally have to trade in some darker parts of the shot and they get clipped out. When boosting exposure, it shows which channels suffer most. Blue is the first I lose and then the Reds. Green is captured rather well when underexposed but even so, there's little I can do with those ugly parts. Unless I desaturate.

J-see said:

I can't de-noise each channel but if you can, give it a try and tell me how it works.

It's also very obvious in night shots that the three channels are not equally distributed. If I gather light, I occasionally have to trade in some darker parts of the shot and they get clipped out. When boosting exposure, it shows which channels suffer most. Blue is the first I lose and then the Reds. Green is captured rather well when underexposed but even so, there's little I can do with those ugly parts. Unless I desaturate.

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I think it may be possible in DFine, as I think you can work on individual channels... I'll give it a go a report back!

Looking at some YouTube videos, working on individual colour channels is possible - I'm at work right now and watching with no sound, so I'll look again properly when I get home!

I saved as a TIFF and used the (non)practical noise reduction in the individual channels in my old PS. I did heavy reduction on the Blue, half of that in the Red and none in the Green. I then saved and went to LR again upping luminance noise to 20 and slightly increased exposure, contrast and a bit of saturation to compensate for some losses.





It's not completely gone but it doesn't rule no longer. With some fine-tuning you probably get better results.

That looks much cleaner J-see, I'll have a good crack at that tonight - It looks like working on individual colour channels is the secret! Thanks very much

You're welcome.

The shots with faces might prove more difficult especially when tweaking the individual channels. The shot directly gets a slightly different overall tone even when doing minor adjustment and while it doesn't matter that much for most content, I can imagine skin could quickly look very strange.

I'll have a go tonight and see where I get - There are only a few shots out of the 200+ I took which suffer, so its not a big problem if I just drop those shots - I really just wonder for future reference. Other shots are between ISO 3-5000 and the noise is much more manageable. I think this is the first time I have taken my D7100 to ISO 6400, and perhaps it is best used for things other than faces!

I don't know about the D7100 but the D750 can manage quite some noise as long as I overexpose. If I need ISO 3200, I rather go one stop higher since that allows me to overexpose one stop more. Overexposed shots as 6400 usually work out better than correctly exposed at 3200. I use 0.3-1 for everything up to 2-3k and 1 to 2 stops for everything higher.

Even when birding and I can't gain that stop anywhere, I switch to matrix metering instead of center (if the environment is darker than the bird). That way the bird will become slightly overexposed automatically.

A great thing about the D750 is that I can even use exposure compensation in manual mode. My D3300 didn't do that.

If you really want to process quite a lot of shots then here is what Topaz Labs DeNoise 5 can do in a single click.

These are 100% crops of your original
1st original
2nd setting set to RAW moderate
3rd set to RAW strong.

The second one is some pretty good reduction. Makes you wonder why you do all that effort manually.

wornish said:

If you really want to process quite a lot of shots then here is what Topaz Labs DeNoise 5 can do in a single click.

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A big +1 from me for Topaz Labs software.

I've always found masking to be a stone-cold b---h to do in Photoshop but a "free" copy of their "ReMask" software was included with a recent 5-Day Deal I picked up and I have to say, ReMask is nothing short of remarkable. Soooooo much faster and easier to use. I've often thought of investing in some other Topaz products but I just tapped my credit limit pretty hard this morning so new software is going to have to wait.

....