Too much noise?

[TheBigE]

I was wondering if I was pixel peeping too much on this photograph

This was shot at 800 ISO, 1/250s, 10mm f/11 on my D7200. I did a transform on the image in LR and was looking a bit at some of the detail. For this, I basically held my arms out over the bridge with camera pointed straight down and fired off a couple shots of the top of the vessel going under the bridge. The ship was carrying cargo trucks as you can see.

In the photograph the sun was coming from the top - basically it was setting. I think you can see this on the shadows in the container trucks. The dark black in the area between the trucks seems very clean. I am looking at the shadows in on the top of the trucks - these seem noisy. I was playing around a bit with NR in LR to see if this could improve.

Is that real noise in the shadows? Is it the texture of the top of the trucks? Just looking for some input. Thanks

[Dave Humphries]

We can't see from these images Erik,

Can you upload a small portion of the shot; e.g. make a 700 x 700 crop of an area that shows a gap and some of the ridges and shadows you're concerned with. Obviously from the full resolution image on your computer, not what's already been uploaded.

We'll then be able to see what you are; e.g. 1 camera pixel = one display pixel.

TIA, Dave

[Manfred M]

+1 to what Dave has written.

How much noise is acceptable is very much a personal call. The final product also influences the decision. I have a much lower tolerance for noise is a large print than I do in a posting on the Internet. Certain subject matter can handle digital noise better than others.

[TheBigE]

So I think I have this right - did a 700 x 700 crop in PS and then exported as JPG. Here is the photo at original size from my SM Gallery



I fully understand this is a bit of personal taste and where it is going to be used. I am just tryin to learn my equipment better....for me I was not expecting what I think is noise in the light shadows on top of the container....

[Mike Buckley]

My general guideline regarding noise is that I don't concern myself with it if I can't see it when reviewing an image at 30% or less. (30% is much larger than anything displayed in entirety on a computer monitor.) If I have the need to review at larger than that, such as when making a large print, and if noise is present, I'll deal with it at that time and only at that time.

Your first image posted here is a perfect example of that approach. Noise can't be seen at this size at least not to my eyes. So, I wouldn't be concerned with even the possibility of noise until indeed I can see it when I want to display the image at a larger size.

[TheBigE]

My general guideline regarding noise is that I don't concern myself with it if I can't see it when reviewing an image at 30% or less. (30% is much larger than anything displayed in entirety on a computer monitor.) If I have the need to review at larger than that, such as when making a large print, and if noise is present, I'll deal with it at that time and only at that time.

Your image posted here is a perfect example of that approach. Noise can't be seen at this size at least not to my eyes. So, I wouldn't be concerned with even the possibility of noise until indeed I can see it when I want to display it at a larger size.

Tnanks Mike - I agree on the computer and screen this image is fine - only when I start zooming in do I see some noise i really was not expecting. My goals is to understand the limitations of my equipment such that someday when I do come across that image I can maximize my chances of getting in right in camera to be blown up and placed over the fireplace.

[Mike Buckley]

This doesn't look like noise to me; the shadow areas have the same characteristics as the bright areas though of course darker. Others may disagree.

[TheBigE]

This doesn't look like noise to me; the shadow areas have the same characteristics as the bright areas though of course darker. Others may disagree.

Similar to what I was thinking - I would expect the dark areas in between the containers to exhibt some amount of noise as well. I am not seeing that in this photo.

[Mike Buckley]

I would expect the dark areas in between the containers to exhibt some amount of noise as well.

Why would you expect that? My experience is that all areas including the dark areas of a properly exposed image that are also in focus will display no noise unless of course a really high ISO value is used.

[Arjung]

I find the noise quite odd for a d7200 at an ISO of 800. I have a d800 which, although a FF is an older camera. It has more noise than a d7200. I enjoy shooting wildlife photography and some of the best images come at dawn & dusk. In order to capture motion I need to have shutter speeds ideally of over 500 to avoid any camera shake (the drawbacks of a large mp camera).

My way out is to increase the ISO which I push up frequently to 6400. This image is shot at ISO 6400 1/1000 5.6 and is a large 30" X 20" print on my wall. It is straightened (no crop) so the size has shrunk by 10% from 7630x4912 to 4507x6753 pixels. Unless you look at the print from a foot you cannot notice the noise

[Black Pearl]

I don't think that is noise so much as the inherent grittiness of that particular sensor at pretty much any ISO that isn't base. Not that that is a worry as at normal viewing sizes and when printing it simply doesn't show.

[NorthernFocus]

That's a tough one to determine, Erik. My first inclination is that it looks like noise. Particularly because it seems worse in the shaded area. But by the same token if the shadows are noisy you'd surely expect to see noise in the dark shadow between the crates. So I'm less inclined to say it's noise.

I've shot a D7200 a good bit. I also shoot a D810 for comparison. The 7200 controls noise pretty well and compares favorably to the D810. I don't hesitate to shoot up to ISO1600 with the D7200. i'll go higher but beyond that apply noise reduction in post will likely be necessary depending on subject and end use in mind. All of this presupposes that you shoot RAW.

[ajohnw]

I put that sort of thing down to a different type of noise that I believe is called chroma noise. At least in part it's due to a miss balance in the channels noise levels / response to light levels. Looking at the dark areas in the crop I feel I can just about see noise that is predominantly red. Brighter areas blue come yellowish in places. On my D7000 the best description of the colour was more or less black and could occur at any luminance level. If I brighten up an image from an 80D I recently bought very dark areas have a lot of green noise in them. Fortunately it didn't need brightening to a point where this would show.

John
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[Dave Humphries]

Thanks for posting exactly what I was after Erik,

Regarding the apparent cleanliness of the dark shadow areas, this is likely because you may have applied some 'Adobe default' sharpening and noise reduction (NR) in LightRoom (LR) - which I think you are using.

I always turn both to zero and deal with both issues at an appropriate point in my workflow by other means (I don't like Adobe NR and I sharpen the output in PS because I use ACR+PS, not LR), but other's mileages do vary, necessarily.

Anyway; part of the way NR usually works will be to assume that we don't want to see noise in the dark shadows, so it deliberately applies more NR there, risking losing fine detail (that the eye won't register because its dark).
When it comes to the mid tones though, it can't differentiate noise from fine detail, so it leaves it alone. Hence more noise in the mid-tones.


If the noise bothers you (on another image, say), I'd suggest using a form of NR that samples from the image to identify noise - i.e. you 'give' it a mid-tone sample area that is lacking fine detail and it analyses that, identifies the noise 'signature', then subtracts that across the entire image. I personally use Neat Image, but I believe there are other third party methods that appear to be as effective, although whether they work the same way, I know not.

Cheers,
Dave

[TheBigE]

Good feedback from everyone - I went back and looked at the original image in LR. This photo has all LR Noise Reduction and Sharpening turned off. I just balanced the blacks and whites and minor adjustments in Exposure, Shadows and Highlights. It is shown below



Interestingly I enlarged "roughly" the same area.



So the later is pretty much right out of camera - I am not seeing a great deal of noise, maybe a touch in the shadows of the rails.

I guess my PP work really helped emphasize the noise in the image. Realistically - from viewing this on screen, it is no issue and even printing I am sure this would not be an issue. I would like to have just a touch cleaner image. For that I started down the path and looking at some of the external NR editors. I noticed TOPAZ filter has had good reviews and has a free download for trial as well. I might give that a try as well as a few others.

[Dave Humphries]

~ I noticed TOPAZ filter has had good reviews and has a free download for trial as well. I might give that a try as well as a few others.

I have seen good results from others here using Topaz too, although I've not tried it myself.

I realise, re-reading my post above, that I overlooked to mention that most sharpening also has a control to limit how much is applied in shadow areas; e.g. "Threshold" in USM (UnSharp Mask), but by another name in different filters. This should be raised (numerically) on noisy images and lowered on low noise ones, to give better fine detail sharpening.

When I output sharpen in PS CC, I currently use USM (after downsizing to web screen size) for on line display OR Smart Sharpen when saving a (full resolution/size) 'Print' version.

[ajohnw]

I don't use PS or Lightroom. I have PS but don't like it. I have noticed and odd effect on one package I use that relates to noise. Other packages may work the same way. They process the images in steps as they are applied each one working on the results of the last one. I've found that it's best to get rid of noise first or at least as early as possible. The thought only occurred recently but on the package I mostly use there does seem to be some mileage in it.

John
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[Manfred M]

Erik - I use the Nik Dfine NR filters. It has always had good reviews and the price is right - FREE (the package was quite expensive when I bought it a number of years ago).

As I generally shoot at or near base ISO and tend to monitor my shots quite closely at higher ISO, I find I rarely need to use any NR filters.

[NorthernFocus]

...I've found that it's best to get rid of noise first or at least as early as possible...

Definitely. Noise is simply bright pixels. So any increase in contrast, "clarity", etc, will make noise more pronounced. Optimally eliminating noise would be the first step of PP. Not always practical nor necessary. But that would be the best way to apply NR.

[TheBigE]

Definitely. Noise is simply bright pixels. So any increase in contrast, "clarity", etc, will make noise more pronounced. Optimally eliminating noise would be the first step of PP. Not always practical nor necessary. But that would be the best way to apply NR.

Yes, that is what I am learning from this exercise. I would not normally expect that 800 ISO has significant amount of Noise, but with this sensor it certainly does have some noise and that is exaggerated with the PP work that was done.

When I have a minute I am going to go back and try NR first (NIK Dfine) and then apply the remainder of the PP and see if there is a significant difference.