Where Does All the Noise Come From?

redleash · October 24, 2015

I seem to be seeing unexpected noise in a lot of my images. I am using a Nikon D300S. This occurs with all three of my regular lenses (Nikon 70-300 f4-5.6, Tamron 17-50 f2.8, Sigma 10-20 f4-5.6). I just looked at a shot i took a couple of weeks ago and there is excessive noise in the sky--when the weather was clear at midday and I shot at ISO 200, f8 and 1/1000. I did have a -1 exposure comp but that shouldn't have caused the noise, should it? Other shots under similar conditions but with less or no exp comp showed the same amount of noise--and sometimes no noise at all. It seems pretty random, although lately I have noticed it more.

This is a fairly new problem (in the past 6 months or so). Could it be a problem with gear? I wondered if it could be the settings I choose but if so then I should have been seeing this a long time ago. Or maybe my images have always been noisy but I am only now aware of it since my cataract surgery? Regardless of the cause, I am seeking a solution.

As an aside, my one complaint about this camera has been noise. It is supposed to be usable at higher ISO but I try to avoid anything at or above 800 because I know there will be too much noise. In the past, my shots at 200 or 400 have been fine, until the last few months. I shoot primarily landscapes or other non-moving outdoor subjects so I seldom have the need to shoot at higher ISO. But it would be nice if the camera performed better in that respect.

Any ideas or suggestions? Also, what do y'all use for noise reduction? I can usually succeed at reducing the noise sufficiently to make a better image, except that it softens everything. I keep experimenting to find a solution I like but I welcome any tips.

Thanks,
Lauren

kdog · October 25, 2015

Hi Lauren,

Shooting at EV -1 itself won't increase noise, however increasing exposure in post processing to make up for it definitely will. Anything without texture like the sky is one of the first places you'll notice noise. Adding global sharpening to an image also sharpens noise and makes it more noticeable. You should never sharpen a sky for that reason.

I think its unlikely that your camera is malfunctioning. It's probably a combination of how you're shooting, your post processing workflow, your eyesight, and the fact that you're probably getting more discriminating about your photography over time. Sad to say the D300s is getting a little long in the tooth compared to more modern cameras with better sensors.

Sam · October 25, 2015

Lauren,

Here is a link to a 2009 review of you Nikon D300S. While I didn't read very much I did look at the noise comparison between the Nikon D300S, and the Canon 7D, and they seem to be on a par with each other.

http://www.dpreview.com/reviews/nikond300s/15

I have a 7D and while it has it's pluses high ISO shooting is not one of them, so I wouldn't expect your Nikon D300S to be stellar at high ISO.

Maybe it's time to consider a newer model? Perhaps a full frame jobby?

Like Kdog says, (he is teaching me to shoot at higher and higher ISO's)*, don't underexpose, and push in post, Also be careful opening shadows.

Basically there isn't any reason to shoot landscapes with high ISO, and you can very easily process the sky separately from the ground to end up with a noise free sky and all the detail your camera is capable of for the ground.

* My name is Sam and I am afflicted with severe "PN" phobia. PN stands for photo noise. photo noise assails my senses, silently screams in my psyche, with side effects of insomnia, and panic attacks. But with therapy and time I will overcome this and be able to set my camera at ISO 3200 or (gulp) even higher.

Sam

ziggy53 · October 25, 2015

Try to find other local professional photographers and let them look at your original image files. If they think that you have a problem, perhaps they can make settings suggestions. If you want us to assess images then we need to see the original image file in order to make a value judgement.

1) I use Neat Image (NI) noise reduction software, mostly because it has the ability to analyse the image by a number of criteria, create a profile automatically and let you tweak the profile to your visual preference (according to results in a small crop) before running against the entire image. You can also apply pre-made profiles and design your own profiles to save for similar images.

NI is also extremely effective for film scans, which I sometimes do.

It gets very nice reviews from photographic heavy hitters like:

Norman Koren (reviewing for film scans, but much of the review also applies to digital camera files)

Michael Reichmann, The Luminous Landscape (2009 review, but it's still relevant)

When I want to apply noise reduction to just certain areas I build layers of original image and noise processed image, and then use Photoshop's masking and compositing capabilities to combine the layers to produce best results.

2) Noise Ninja is the other noise reduction software I looked at that gets very good reviews, but Neat Image (PS plugin plus standalone) was a better fit to my specific needs.

3) Raw Therapee is freeware image processing (both RAW files and other raster image files) which has some wonderful noise reduction capabilities including:

General Noise Reduction (NR): This is a very comprehensive panel, so it's best to review the available functions here: http://50.87.144.65/~rt/w/index.php?title=Noise_Reduction
Impulse NR: Mostly for scanned images, but sometimes usable for really underexposed images too.
Wavelets and NR: (Specifically Daubechies wavelets) allows you to "slice" (decompose) the image into levels of detail, plus a residual image. Then you apply noise reduction according to a specific detail level only, or several detail levels simultaneously. The effect is highly controllable noise reduction. Wavelet levels can be so specific as to allow stain reduction too. Extremely powerful tool.

redleash · October 25, 2015

Gentlemen,

Thanks for the helpful info and suggestions. As for sharpening, I tend to do very little but I will keep an eye on it. Joel, I have indeed seen noise increase when adjusting exposure in post so I don't do it if I can help it. In the shots I looked at before I wrote the orig post, the noise is in the sky, but I did not adjust the exposure nor sharpen the sky so I don't think I added anything. I could be wrong for sure. I am out of practice with shooting and PP but have a lot of shots I want to catch up on, including the ones I brought back from Maine that are some of the problem images. (And now that it is cooling off here I can start shooting more.) I will go back and do more detailed PP with the sky and ground separately.

I will look into the Neat Image software. I use different NR processes depending on what the image looks like: Topaz Denoise or the NR built into other Topaz products, Photoshop or ACR. I am just learning Lightroom so I have not used its NR feature.

I have begun thinking about a new camera but have not even started to research them yet. I expect I will stay with Nikon, although I am ready to replace my two main lenses anyway so I may give thought to Canon.

I will upload a couple of original files for you to take a gander at and will post the link here.

Thanks for all the great help! You three were the shooters I expected I would hear from on this.

Lauren

Richard · October 26, 2015

I see noisy skies one in a while from my 50D for no apparent reason--low ISO, proper exposure, etc. I've never understood why, but have just learned to fix it in post.

The noise correction stuff in LR is the same as in ACR, so it should be nothing new for you. It works pretty well for me up through ISO 1600, but after that I use Noiseware instead when needed. ACR/LR noise reduction only works globally, while specialized products let you target the effects narrowly, by color range, tonality, and other factors. I chose that one over Noise Ninja and Neat Image because I thought the UI was better designed, but I suspect all three are about comparable in effectiveness. I created a custom preset that limits its action to blue skies only while leaving the rest of the image alone. You can achieve the same result by doing the noise reduction on a separate layer and masking out everything but the sky. Since the changes are subtle, the mask doesn't have to be very precise.

puzzledpaul · October 26, 2015

Richard wrote: »

... I use Noiseware instead when needed. ....

You can achieve the same result by doing the noise reduction on a separate layer and masking out everything but the sky. Since the changes are subtle, the mask doesn't have to be very precise.

Whilst I generally don't shoot landscapes and don't have sky in many of my bird pics, I suspect that large areas of very oof bg (and sometimes fg) present similar problems as sky, with their gentle and subtle colour transitions ... so I use similar techniques (and s/w) when I feel the need.

After reading Ziggy's recommendation for NI, I'll check it out,though.

pp

JonaBeth Russell · October 26, 2015

I shoot a 7D and occasionally get noise on blue-sky images, as well as shadows in a highly contrasting scene. I've found that if I slightly overexpose (+1/3), with post in mind, the noise is non existent and the detail remains. However, as pointed out by others, if I properly expose, or even shoot a tad under, the shadows need NR in post on any image shot above 320 ISO.

I like LR's NR personally. I don't mind that it's global, although I can do masking and such to isolate particular areas of an image. The fact that it's somewhat limited forces me to learn how to more properly light a scene, rather than rely on post to correct.

For lower light conditions, I find that shooting medium RAW creates a much cleaner image than large RAW (interpolation comes into play). This way, I can shoot at 3200, 4,000 and, in some cases, 6400 with proper flash lighting without it looking like it was taken on an old 3mp point and shoot. A medium RAW file can still print up to 20 inches on the long side when exported at 200 pixels per inch...plenty enough for a photo that size.

redleash · October 28, 2015

Thanks everyone--more helpful info. Had never thought about file size--might give that a try.

JonaBeth Russell · October 29, 2015

Here's an image shot on my 7D mk I at 5,000 ISO, using a Canon EF-S 17-55 f/2.8. Only available light was my speedlite 430EX II. This image was shot in Large RAW, but the quality is still pretty fair, if I might say so myself. I later switched to Medium RAW and the images got better. I was testing the scene for a step & repeat spot at a rehearsal dinner

Where Does All the Noise Come From?

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