Noise reduction for nicer pics??

How often do you use NR?

I always thought noise reduction was just for high iso or low light shots with obvious grain showing. But I was playing around with it on some pictures and noticed a nice smooth sharper look to them after nr that I always attributed to better cameras or lenses. So am I nuts or is nr much more important to a pleasing photo then I thought even on iso100?

I use it whenever I need it. Mostly just a bit of chroma NR.
Occasionally a touch of luminance NR on high ISO shots.

Rene- In what capacity should the in camera NR be turned on for? I am aware of astro photography byut can you use it in other apps such as very high ISO shooting like indoors? I am curious if it is applicable to use the in camera NR opposed to PP NR software instead if you can.

I do not use in camera noise reduction. Shoot in RAW and make your adjustments later.

That seems to be the ongoing conscensus. To play devil's advocate though, why not do it in camera lessening the amount of PP work to be done later?

mr2step wrote in post #12786693
That seems to be the ongoing conscensus. To play devil's advocate though, why not do it in camera lessening the amount of PP work to be done later?

Someone can correct me if I'm wrong, but my understanding is that 'in camera noise reduction' does not apply to Raw images.

That's correct, and the advantage of applying it in post is that you can balance the amount of noise reduction with loss of detail ...along with the many other advantages of shooting RAW.

My understanding of the in-camera noise-reduction is that it removes the dark current and bias signal noise from images (eg repeatable hot pixels and the signal readout noise of the sensor/electronics).

To do the dark current noise reduction, the camera needs to take an image of the same duration as the actual exposure you want, but with the shutter closed, then it subtracts that signal from your exposure. So if you take a 30 second exposure, it'll take your 30 sec shot, then take 30 secs more for the dark, then it'll save to your card. Because the dark current also contains the bias signal, it gets removed at the same time by default.

You can't do that in post-processing. It needs to be captured in-camera. And I could be wrong, but I'm pretty sure it's applied to the RAW and JPGs.

There are other types and sources of noise, the above only removes those types mentioned. If your exposures are short enough, the dark noise probably isn't that much of an issue. We are more aware of it with astro-imaging because we have extremely long exposures of very dark subjects so signal to noise ratios is much, much, much lower than for "normal" photography.

For all other types of noise reduction, for normal photography, your typical NR software is the only way to go. They'll probably handle the dark and bias as well, but I reckon the best results are to let the camera do that work for you.

Another thing to consider is your intended final output. Does the noise you see at 100% zoom in a 18Mpx image really translate to any meaningful artifact in an image printed at 5x7? Is it entirely different when the intent is for 800px wide web display? What processing workflow do you use to get to that final result, and does your editing bring out what was once tolerable (or even desirable) noise?

As you might expect, there is probably not a one-size-fits-all answer.

Kirk

Great insight and on point regarding the hot pixels that get subtracted with in camera noise. I was just curious as to everyones input and really appreciate it all.

I've used noise reduction four times in the 200,000 or more wedding photos i've taken, and I shoot a LOT of high iso. I don't count my raw processors built in noise reduction. I just don't care about noise, and apparently neither do my customers. In that time one customer has mentioned noise/grain in one image, when I told them the technical reason (mixing ambient light with flash in the proportions I wanted) they were happy with it.

Print generally don't show much noise.

Good points, Tim. While I'm not a professional, I've found that as long as the exposure is close to right and you're not trying to stretch the dark end of the histogram up too much, the noise is not a problem.

pxchoi wrote in post #12786744
Someone can correct me if I'm wrong, but my understanding is that 'in camera noise reduction' does not apply to Raw images.

Wrong

Frugal wrote in post #12787212
That's correct, and the advantage of applying it in post is that you can balance the amount of noise reduction with loss of detail ...along with the many other advantages of shooting RAW.

Wrong You can not do high iso noise reduction the camera does after the fact in raw software. You can take multiple images and do it by hand though(which would take alot more time).

troypiggo wrote in post #12788296
My understanding of the in-camera noise-reduction is that it removes the dark current and bias signal noise from images (eg repeatable hot pixels and the signal readout noise of the sensor/electronics).

To do the dark current noise reduction, the camera needs to take an image of the same duration as the actual exposure you want, but with the shutter closed, then it subtracts that signal from your exposure. So if you take a 30 second exposure, it'll take your 30 sec shot, then take 30 secs more for the dark, then it'll save to your card. Because the dark current also contains the bias signal, it gets removed at the same time by default.

+1 Tim. I dont care that much either

You can't do that in post-processing. It needs to be captured in-camera. And I could be wrong, but I'm pretty sure it's applied to the RAW and JPGs.

There are other types and sources of noise, the above only removes those types mentioned. If your exposures are short enough, the dark noise probably isn't that much of an issue. We are more aware of it with astro-imaging because we have extremely long exposures of very dark subjects so signal to noise ratios is much, much, much lower than for "normal" photography.

For all other types of noise reduction, for normal photography, your typical NR software is the only way to go. They'll probably handle the dark and bias as well, but I reckon the best results are to let the camera do that work for you.

This is correct. And long exposure noise reduction does apply to RAW and jpeg as you thought. Personally I keep in camera noise reduction off since the only thing that bothers me much is chroma, and the additional time for the exposure to complete isnt worth it.

As for astro noise reduction, often times they will take several photos of different exposures to subtract noise later, using applications like deep sky stacker. Similar but much more powerful than the in camera method.

If you have a still object there is another route you can go, which is to take dozens, or even hundreds of the same image and average them all together. This increases the signal to noise ratio, making details of the object more crisp, and flattening the noise. This wont get rid of hot spots or anything, but it will make random noise appear to be less than what it is, with the added benefit of sharper detail.

As mentioned, there are two types of NR: Dark frame subtraction is done when you set "Long Exposure NR".
The "other" NR is the same kind of NR that can be done in the Raw converter: DPP will read the in camera setting and apply it as a starting point (if you tell it to in the prefs), LR will ignore it.

TheLostVertex wrote in post #12788999
You can not do high iso noise reduction the camera does after the fact in raw software.

Wrong, of course you can.
What you probably mean to say is that you cannot do Long Exposure NR after the fact. And even that is not completely true. You could take a second shot with the lenscap on, then subtract it in software.
(Older camera's, like the 1Ds did exactly this: Take a second exposure, without opening the shutter)

René Damkot wrote in post #12789131
...You could take a second shot with the lenscap on, then subtract it in software.
(Older camera's, like the 1Ds did exactly this: Take a second exposure, without opening the shutter)

That's kind of how we do it for astro. You can use Photoshop to subtract it - I guess either adding it as a layer on top and choosing the subtract blend mode, or pixel maths subtraction but that's a little more complicated.