topic Re: 7D Mark II noise at low iso in EOS DSLR & Mirrorless Cameras

7D Mark II noise at low iso

thegios — Thu, 02 Aug 2018 17:49:04 GMT

This is a 3:1 crop taken with a 7D Mark II with a Canon 17-55 f2.8 lens at 17mm f11 iso 100 1/200 sec: is it normal such a noise on the sky?

Re: 7D Mark II noise at low iso

diverhank — Thu, 02 Aug 2018 18:01:12 GMT

Did you brighten the image in post? Then the answer is yes.

Re: 7D Mark II noise at low iso

thegios — Thu, 02 Aug 2018 18:07:12 GMT

Nope... Just imported in Lightroom, which applies by defult the following sharpening:

- Amount 40

- Radius 1

- Detail 25

- Masking 0

I tried seeting masking to 100 and the problem is a lot mitigated.

Just wondering if this is a normal behaviour.

Re: 7D Mark II noise at low iso

diverhank — Thu, 02 Aug 2018 18:25:17 GMT

Then light room sharpening is the culprit. I usually don't use sharpening at all. Try just a bit of clarity , vibrance and saturation. When you need to sharpen, use a brush and target specific area (avoid the sky).

Re: 7D Mark II noise at low iso

ebiggs1 — Thu, 02 Aug 2018 20:53:00 GMT

"Just imported in Lightroom, ..."

Now you can fix it in LR if it bothers you. Any solid darker color will show some noise even at lower ISOs. NR in LR is under the sliders you listed as the ones edited. The camera also applied some sharpening so you got it twice. You can set that to 0.

Re: 7D Mark II noise at low iso

TCampbell — Fri, 03 Aug 2018 01:10:19 GMT

Can you post the original RAW file?

(you can’t post it here, but if you post it to a Dropbox, Google Drive, etc. account then you can share it with a link.)

Re: 7D Mark II noise at low iso

thegios — Fri, 03 Aug 2018 05:50:58 GMT

@ebiggs1 wrote:
The camera also applied some sharpening so you got it twice. You can set that to 0.

It's a raw file opened in lightroom, so any in camera processing done on the JPG should not affet the preview.

Re: 7D Mark II noise at low iso

thegios — Fri, 03 Aug 2018 05:51:36 GMT

@TCampbell wrote:
Can you post the original RAW file?

(you can’t post it here, but if you post it to a Dropbox, Google Drive, etc. account then you can share it with a link.)

https://www.dropbox.com/s/07htcgtcvo4jlue/_31A9703.CR2?dl=0

here it is 🙂

Re: 7D Mark II noise at low iso

TCampbell — Fri, 03 Aug 2018 15:09:31 GMT

Keep in mind ALL images have noise. I'll avoid the technical discussion on why, the different types of noise, why it is unavoidable, etc.

I imported this to Lightroom.

At 1:1 scale, noise is very low (I have difficulty seeing it with my eyes)

At 4:1 scale (400% zoom) I see noise similar to the section you've posted here.

We sometimes ask people to post a 1:1 crop of an image to show an issue... but usually not a 4:1 crop.

If you needed to produce a very large print, you'd navigate to the "Detail" section of hte Develop module, hold down the 'alt' key, and slide until the sky goes flat black. (For this image, I got that result with the Masking slider set to 9.) The masking slider looks for edges of contrast from flat areas so that "sharpening" occurs only where there are edges but skips areas that are flat (such as the sky). Similarly, de-noising will be emphasized in flat areas, but will be reduced near edges of contrast (to avoid losing details).

Having done this, you can increase the Luminance noise reduction.

I usually try to minimize de-noising so that it's 'just enough'.

Re: 7D Mark II noise at low iso

ebiggs1 — Fri, 03 Aug 2018 15:18:24 GMT

"It's a raw file opened in lightroom, so any in camera processing done on the JPG should not affet the preview."

You may not know, is that Lightroom doesn't automatically apply your camera settings. It uses them and then it converts them back to Adobe Standard. That is why a Raw image that looked great on the cameras LCD and then it looks different on your monitor. However LR does use them for a starting point.

Photos are imported and immediately display the photo's embedded preview. Embedded previews that are created by the camera. All settings applied. However, the embedded previews don't match how LR interprets the Raw files.

Re: 7D Mark II noise at low iso

thegios — Fri, 03 Aug 2018 15:25:14 GMT

TCampbel: that's exactly what I do 😉

ebiggs1: I always use neutral picture style with all values set to zero, to avoid LR from interpreting wrongly any in camera picture style while importing

Re: 7D Mark II noise at low iso

ebiggs1 — Fri, 03 Aug 2018 15:36:02 GMT

"... to avoid LR from interpreting wrongly any in camera picture style while importing"

OK, I think you have a good understanding how LR works.

Re: 7D Mark II noise at low iso

Peter — Sun, 05 Aug 2018 07:29:38 GMT

Photon shot noise:

"An important characteristic of fluctuations obeying Poisson statistics is that their standard deviation -- the typical fluctuation away from the average in the typical count -- is equal to the square root of the average count itself. That is, if 10000 photons are collected on average, the typical fluctuation away from this average number of photons will be about 100 -- the counts will typically range from about 9900 to 10100. If instead on average 100 photons are collected, the variation from count to count will be +/- 10. Thus, as the signal grows, the photon shot noise also grows, but more slowly; and the signal-to-noise ratio increases as the square root of the number of photons collected. The higher the illumination, the less apparent the shot noise; the lower the illumination, the more apparent it is."

Below is the raw histogram from your raw file. You could have collected a lot more photons before clipping the highlights.

Re: 7D Mark II noise at low iso

thegios — Sun, 05 Aug 2018 17:41:11 GMT

Translated: pic is underexposed and therefore noise is higher, I could have increased exposition (as I had plenty of room) to minimize the noise?

Correct?

Re: 7D Mark II noise at low iso

Peter — Sun, 05 Aug 2018 19:06:35 GMT

@thegios wrote:
Translated: pic is underexposed and therefore noise is higher, I could have increased exposition (as I had plenty of room) to minimize the noise?

Correct?

Correct. Collect more light. To check the raw histogram I have used RawTherapee.

Re: 7D Mark II noise at low iso

ebiggs1 — Sun, 05 Aug 2018 23:26:57 GMT

Peter excellent conclusion and explanation.