Curious Image Noise on Low ISO

H

huck

Senior Member
Hey guys! I never get to post like I'd like to because I'm always too busy, but I always use this site for all the great info it has to offer. I've searched the site (and google in general) and didn't find any info related to my exact problem, so I apologize if this is a repost of a common problem.

A few weeks ago I did a photoshoot of a mom and her young son. I was at the beach with a lot of water around me so I threw on a (on the cheaper side) polarizer filter onto my Nikon 70-200 that I've never had any problems with and shot away. When I got home and started editing I noticed a weird, noise-like quality to the pictures, even though I'd shot at ISO100, f/2.8 @ 200mm and 1/2000sec. A lot of the pictures had the effect, looking like severe noise/grain, so I figured it was my cheap CP filter and I'd just never noticed it before, so I tossed it in the trash and moved on.

Fast forward to last week, I was in Fontana Village NC shooting a car-themed engagement set with the same D750 and Nikon 70-200 sans CP filter, and when I got back home and loaded the shots onto my computer I see the same noise in the shots. Weird thing is, it's not all of them, and it's always been at super low ISOs. Any idea what's going on? Wrong setting in the camera, messed up lens, just needs a cleaning? I've never seen this before or heard anyone talk about it, so I'm at a loss. Any help would be appreciated.

And because the pictures don't seem to want to upload here, I'll include links for them. If you zoom in, you can see some serious IQ flaws going on.

https://drive.google.com/open?id=0B6To-aX6nfpEZVVYLWpMckgxZXc

https://drive.google.com/open?id=0B6To-aX6nfpEZ2phTFR5RGJ6QjQ
 
Horoscope Fish

Horoscope Fish

Senior Member
huck said:
Hey guys! I never get to post like I'd like to because I'm always too busy, but I always use this site for all the great info it has to offer. I've searched the site (and google in general) and didn't find any info related to my exact problem, so I apologize if this is a repost of a common problem.

A few weeks ago I did a photoshoot of a mom and her young son. I was at the beach with a lot of water around me so I threw on a (on the cheaper side) polarizer filter onto my Nikon 70-200 that I've never had any problems with and shot away. When I got home and started editing I noticed a weird, noise-like quality to the pictures, even though I'd shot at ISO100, f/2.8 @ 200mm and 1/2000sec. A lot of the pictures had the effect, looking like severe noise/grain, so I figured it was my cheap CP filter and I'd just never noticed it before, so I tossed it in the trash and moved on.

Fast forward to last week, I was in Fontana Village NC shooting a car-themed engagement set with the same D750 and Nikon 70-200 sans CP filter, and when I got back home and loaded the shots onto my computer I see the same noise in the shots. Weird thing is, it's not all of them, and it's always been at super low ISOs. Any idea what's going on? Wrong setting in the camera, messed up lens, just needs a cleaning? I've never seen this before or heard anyone talk about it, so I'm at a loss. Any help would be appreciated.

And because the pictures don't seem to want to upload here, I'll include links for them. If you zoom in, you can see some serious IQ flaws going on.

https://drive.google.com/open?id=0B6To-aX6nfpEZVVYLWpMckgxZXc

https://drive.google.com/open?id=0B6To-aX6nfpEZ2phTFR5RGJ6QjQ
Click to expand...
I downloaded your photos and looked at them in Photoshop and the problem was obvious; more so for me in the beach shot. Can you briefly explain the shot, the time of day was it taken and so forth, if you were shooting JPG or raw, and what post processing you performed on them?

I tried using both Adobe Camera Raw and NIK Tools Dfine to help with the noise and both did a decent job. Camera Raw, I thought, did a better job. Here's an extreme crop of the beach photo, taken from a section towards the upper left corner. As you can see, there is a big improvement after using ACR though refining the settings would result in a better finished product:
.....
.....
No Noise Reduction​
.....
No NR.jpg
.....
.....
.....
.....
After Using Camera Raw​
.....
ACR NR.jpg
.....
 
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H

huck

Senior Member
Thanks for the reply man. Yeah I could use (more) noise reduction in either LR or PS but my main concern is that I've never had to before, and that I shouldn't have that much noise and artifacts present in that kind of a shot at those settings. The beach shot with the little kid was maybe 8-9am, ISO 100 at around 1/1600 sec, and I always shoot in RAW. At ISO 100 there shouldn't be any distortion like that. You can still see sort of what I'm talking about in his hair in the back of the head, it's very pixelated and the colors of his shirt at the collar are the same. I didn't add a whole bunch of effects really, just color correction and some brightness, removing the shadows to better light him up. Upon further inspection, the preset I'm using for this shot somehow got sharpening added to it, and when I reset the sharpening it fixed the problem some, but there's still weird aberrations and colors that I've never seen before. I could understand if this was a long exposure, high-ISO shot. That would be expected. But I shouldn't have noise in full brightness at ISO 100, especially not to this degree.


Image noise.jpgimage noise 2.jpg
 
Horoscope Fish

Horoscope Fish

Senior Member
huck said:
Thanks for the reply man. Yeah I could use (more) noise reduction in either LR or PS but my main concern is that I've never had to before, and that I shouldn't have that much noise and artifacts present in that kind of a shot at those settings. The beach shot with the little kid was maybe 8-9am, ISO 100 at around 1/1600 sec, and I always shoot in RAW. At ISO 100 there shouldn't be any distortion like that. You can still see sort of what I'm talking about in his hair in the back of the head, it's very pixelated and the colors of his shirt at the collar are the same. I didn't add a whole bunch of effects really, just color correction and some brightness, removing the shadows to better light him up. Upon further inspection, the preset I'm using for this shot somehow got sharpening added to it, and when I reset the sharpening it fixed the problem some, but there's still weird aberrations and colors that I've never seen before. I could understand if this was a long exposure, high-ISO shot. That would be expected. But I shouldn't have noise in full brightness at ISO 100, especially not to this degree.
Click to expand...
I'm afraid the best I can do is confirm everything you're saying about these shots; the chroma noise, the distortion... All of it. And I can see it even before zooming in much. I looked over some of my own shots, ones taken with settings as close to yours as I could find, trying to find one that showed the same noise/distortion I'm seeing in your shots and I couldn't even come close. If it were me, I'd try different lenses and see if the problem persists. If it does, it's a safe bet the problem lies with the camera body, if not it's probably a lens issue.

I'm sorry I can't be of any real help in solving the problem but do I hope you get it ironed out.
 
hark

hark

Administrator
Staff member
Super Mod
Did you raise the exposure or shadows during post processing? That can add noise.
 
D

Don Kuykendall_RIP

RIP :(
I do not see the camera listed and that would help if we knew it.

If you fill out your profile and add the camera gear we can better answer any questions that you might have.
You can do that at http://nikonites.com/profile.php?do=editprofile

Under camera just put the model number like D7100; Once you put the first letter like D you will see a list of all the cameras in the database pop up. The more numbers you put in the smaller the list becomes. When you see your camera just click on it, Be sure to click on "Save Changes" in the lower right corner.

Thanks
 
D

Don Kuykendall_RIP

RIP :(
Also full size photos will not upload here.

Guidelines to adding a photo to your post.

1. Resize photo to 1000px on the long side.
2. Resolution set to 72ppi (Pixels Per Inch)

These guidelines will be good for viewing on a computer but will not be good for printing. This will help safeguard your copyright.







 
Horoscope Fish

Horoscope Fish

Senior Member
Don Kuykendall said:
I do not see the camera listed and that would help if we knew it.
Click to expand...
He's shooting a D750 and you can download full size, full-res images from the links in his first post. Or, you can see the EXIF data on the crops I posted of one of his shots in Post #2.

I'd like to see someone figure this out because I'm stumped.
 
BackdoorArts

BackdoorArts

Senior Member
Would be great to see the untouched raw files, and maybe also get a sidecar of the raw edits to see whether or not something there is introducing something.

Going to ask a question about temperatures and distances to subject. I know the beach shot was earlier in the AM and it shouldn't have been that warm, but I know that when shooting wildlife there are times when it's warm enough that you can get heat distortion when you've got enough distance between you and your subject. If this is intermittent and it was warm I'd consider this as a possibility, though I'm thinking it's unlikely.
 
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