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S5 IIX noise reduction -- user error or bug?

PJD

PJD

Well-Known Member
I'm not sure if I misunderstand how the noise reduction features in my new S5iiX camera work, or if maybe there's a bug. The camera has the new 2.0 firmware installed.

I'm not noticing any significant change in carefully-shot 24MP RAW test images when I set "[Camera] | Image Quality 1 | Long exposure NR" = ON, and "Quick Menu | NR" = [_ANY_ value].

To see what or if the camera's NR function does, I locked my camera on a tripod and purposely shot at ISO 6400 in a darkened room so I could set exposure for about 4 seconds. I shot in manual mode, with "iA" turned off, Standard photo style, nothing automatic except for focus & a 2-sec shutter delay.

For the first image I set the Quick Menu | NR to zero, and then shot several additional images, each with QM | NR = +1, +2, +3, etc., and also -1, -2, -3, etc. After each shutter press, the camera displays a message saying the long exposure noise reduction process is taking place.

When I look at the resulting images at 100% view on my Mac in the latest versions of both Affinity Photo 2 and Pixelmator Pro (with _NO_ corrections performed on the images), the images all look "essentially" identical. As expected, individual pixels shift a tiny bit from image to image, but there's no obvious noise reduction/removal. I'd expect the -5 and +5 to look very different than the "zero NR" image, but they're not.

So, is this user error? Anyone else seeing similar results?

(Meanwhile, two points: I don't usually shoot at ISO 6400, but did so for this test. And: Affinity Photo 2's noise reduction feature works really well, so I'll probably rely on it instead of whatever the camera can do. But I'm curious what the camera is capable of.)
 
... oh, wait: Is NR a JPEG-only feature which has no effect on RAW images? :rolleyes:
 
PJD said:
... oh, wait: Is NR a JPEG-only feature which has no effect on RAW images? :rolleyes:
Click to expand...
I've never used this feature but from reading lots of forum posts over the years, I believe that LENR (long exposure noise reduction) does affect the RAW image but changing NR in the Quick menu is only changing the photo style output which is JPEG only.
 
OK, I just shot a series of JPEG images using the camera's NR features as described above. In the JPEGs I can see a difference in NR, especially between the extreme settings. Make sense if NR is a JPEG-only feature. (But I almost never shoot JPEGs, so Affinity Photo 2 will be my go-to NR solution for RAW images when needed.)

Cheers.
 
I think long exposure noise reduction is related to "hot" pixels, rather than less noise?
 
Interesting. Isn't that what "Pixel Refresh" in the wrench menu is for?
 
Every digital camera will develop “hot” or “stuck” pixels over the time. Normally you will not see them with daylight short shutter speed photography. You will see them "easier" when you’re taking long exposures. The easiest way to fix hot pixels is with that "long exposure noise reduction". This feature takes 2 images one after the other. One with your real image and one with a closed shutter (dark frame) without any image. Thanks to this dark frame the camera will be able to recognize if and where there are hot pixels and corrects them then. This is not a Lumix only feature. All brands have this feature nowadays.
 
Thanks for that Dirk, but again: I thought the S5iiX "Pixel Refresh" feature is what we use to proactively remove hot/stuck pixels. If I understand your comment, you're saying "LENR" is separate (in addition) to Pixel Refresh, and is performed immediately after a long exposure photo is taken.

I wonder if just before taking a long exposure photo, if I first use the Pixel Refresh function, does that produce the same result as LENR?

(And again, I'm only taking RAW photos, not JPEG.)
 
PJD said:
I wonder if just before taking a long exposure photo, if I first use the Pixel Refresh function, does that produce the same result as LENR?
Click to expand...

There can be different causes for stuck/hot pixel. One is long exposure because the sensors gets warmer and they are only visible then. Please bear in mind that the exposure time for the "dark frame" has the same time as the image. So you can not use this feature in all situations, i.e. if something is moving. Then you need a different solution.

There are also stuck/hotpixel you always can see if you search for it, even without a hot sensor or long exposure. In that case you use the Pixel Refresh function.

As far as I understood it, hot pixel can appear appear even if you made Pixel Refresh function beforehand at long exposures. But do not quote me on that. here is a video about Pixel Refresh function:


 
Technique of today's cameras is so well developed, that you seldom find "real" difficulties in relation to "hot" or "dead" pixels.

About 22 years ago I used a Nikon D1x camera.
Found a copy of what I wrote in those days at a community by using a special utility that did count the hot-pixels.
As for reference.

Nice, I want to give my results too for a Nikon D1X You can laugh, and still I don't have problems with my camera. It makes wonderfull pictures.
Threshold for hot pixels 60
Threshold for dead pixels 250
First number in seconds is exposure time.

ISO set at 125 (most low setting for D1X)

  • 2 seconds --> 1 hot pixel
  • 4 seconds --> 4 hot pixels
  • 8 seconds --> 7 hot pixels
  • 15 seconds --> 23 hot pixels
  • 30 seconds --> 833 hot pixels
  • 1 min.(64 sec) --> 9327 hot pixels
ISO set at 800

  • 1/4 second --> 2 hot pixels
  • 1/2 second --> 4 hot pixels
  • 1 second --> 7 hot pixels
  • 2 second --> 15 hot pixels
  • 4 second --> 503 hot pixels
  • 8 second --> 6662 hot pixels
  • 15 second --> 34169 hot pixels
  • 30 second --> 113466 hot pixels
  • 1 min.(64 sec) --> 271209 hot pixels
The last values, LOL - LOL - LOL

You have to remember that with a setting of 800 ISO, under normal circumstances shooting at night
in e.g. a city with street lights, you never shall get those long exposure times.
------------------------------------------
Some utilities / programmes':

Huygens Hot Cold Pixel Remover | Scientific Volume Imaging

Scientific Volume Imaging to provides reliable, high quality, easy to use image processing tools for scientists working in light microscopy. Together with a dedicated team in close contact with the international scientific microscopic community, we continuously improve our software, keeping it...
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Pixel Fixer | Hot pixel removal utility

Pixel Fixer is a hot pixel removal utility for digital cameras which works by removing hot, stuck or dead pixels from the raw files produced by your camera. It can also be used to remove hot strips (vertical lines which sometimes appear in conjunction with a hot pixel). Pixel Fixer can be used...
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en.ids-imaging.com

Adaptive hot pixel correction | IDS

The new adaptive hot pixel correction makes it easy to detect and correct disturbing hot pixels on site.
en.ids-imaging.com
 
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