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LX100 - noise on photo of complete darkness - is it good or bad result?

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mdobrou

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Hi,

I have Panasonic LX100.

I took photo in dark with cap on lens. So theoretically, everything should be black (theoretically!).

I expected some noise, but I was little bit surprised with the result.

With "Long shutter noise reduction" feature turned OFF:

cropped RAW - 1:1 - noise reduction off, 60sec, F1.7, ISO200

cropped RAW - 1:1 - noise reduction off, 60sec, F1.7, ISO200

Original RAW here
Original JPEG here

Is this good or bad result?
I expected much less noise. I'm especially concerned about larger dots.

I took multiple shots, all of them had same pattern of noise dots.
So it looks like broken pixels on camera sensor.
Is this common level of noise in such situation? Or is it possible my camera is somehow broken? Can somebody with LX100 compare with his results?

BTW: As expected, with "Long shutter noise reduction" turned ON, no noise is visible without additional brightness changes.

Thank you for advice in advance.
 
You have made a test that bears no relationship to photography. I appreciate that you have asked a question that requires a scientific explanation. Not being a scientist, I have no answer.

Photography is the science/art/craft of writing with light. Your challenge is one of writing without light. Your question seems more appropriate for a forum where the gurus of electronics speak. Maybe there are a few here.

I think your question is valid. I just doubt that it has been asked in an appropriate forum.

Richard Weisgrau
www.drawnwithlight.com
 
mdobrou said:
Hi,

I have Panasonic LX100.

I took photo in dark with cap on lens. So theoretically, everything should be black (theoretically!).

I expected some noise, but I was little bit surprised with the result.

With "Long shutter noise reduction" feature turned OFF:

cropped RAW - 1:1 - noise reduction off, 60sec, F1.7, ISO200

cropped RAW - 1:1 - noise reduction off, 60sec, F1.7, ISO200

Original RAW hereOriginal JPEG here

Is this good or bad result?
I expected much less noise. I'm especially concerned about larger dots.

I took multiple shots, all of them had same pattern of noise dots.
So it looks like broken pixels on camera sensor.
Is this common level of noise in such situation? Or is it possible my camera is somehow broken? Can somebody with LX100 compare with his results?

BTW: As expected, with "Long shutter noise reduction" turned ON, no noise is visible without additional brightness changes.

Thank you for advice in advance.
Click to expand...
Thw Panasonic engineers - realizing that there could be oversenietive ("hot") pixils and/or the sensor can pick up stray X-rays and other radiation such as cosmic rays - provided you with a "Long shutter noise reduction".

So you turned it off and got an image including some "hot pixils".

It's normal, your camera is fine.

When taking long exposures, turn it "ON", that's what it's FOR.

Richard Weisgrau, above, is correct - it's not a photographic problem ,it's an electronic problem, which the engineers have solved. :-D



--
"Measure wealth not by things you have but by things for which you would not take money"
www.flickr.com/ohlsonmh/ [email protected]
 
Last edited:

LX100

Hi, Welcome to the forum. I think that opening the shutter with no light entering the lens is not an activity for which the camera was designed. It is unlikely that there is anything wrong with it.

You might find taking photos more fun.

Good luck

Andrew
 
As Erik Ohlson explained, these were hot pixel, not noise. No sensor could be free from it no matter of its sensor size, or what type of sensor technology would be employed. Some might be more worse than others.

However, LX100's sensor, a Panny 16M latest generation one, is one of those less affected sensors. For some FF sensors which are well known for their intolerance to heat, the result would be even poorer.

You may repeat you test (actually when I bought a new camera, I'll do the same to test for the dead pixel of LCD) but shoot at at much faster shutter speed like 1/10" or so, you would get a perfectly black images.
 
Thank you for answers!

I should have provided better example. My concern was not exactly about photos with lens cap closed. But more about long exposure photos, even with "noise reduction" enabled.

Noise reduction "clears" hot pixels from photo and it has to put something there instead of cleared hot pixels.
So color of such pixels is computed from pixels around.
So places with hot pixels may be less sharp etc.
So more hot pixels results in slightly lower quality of photo.

So I wondered if count of hot pixels of my LX100 is usual.
 
mdobrou said:
Thank you for answers!

I should have provided better example. My concern was not exactly about photos with lens cap closed. But more about long exposure photos, even with "noise reduction" enabled.

Noise reduction "clears" hot pixels from photo and it has to put something there instead of cleared hot pixels.
So color of such pixels is computed from pixels around.
So places with hot pixels may be less sharp etc.
So more hot pixels results in slightly lower quality of photo.

So I wondered if count of hot pixels of my LX100 is usual.
Click to expand...
If long shutter must be used, hot pixel would more or less a problem never go away. Long Exposure NR could minimized the effect of the problem or using PP photo stacking to the similar effect (If I am not wrong, unlike normal NR, Long Exposure NR should act like PP photo stacking to exclude the noise and hot pixel.) Regarding your original sample, the hot pixel was actually not that serious considering a 1 minute exposure.
 
alcelc said:
If long shutter must be used, hot pixel would more or less a problem never go away. Long Exposure NR could minimized the effect of the problem or using PP photo stacking to the similar effect (If I am not wrong, unlike normal NR, Long Exposure NR should act like PP photo stacking to exclude the noise and hot pixel.) Regarding your original sample, the hot pixel was actually not that serious considering a 1 minute exposure.
Click to expand...
Photo stacking likely wouldn't result in removal of hot pixels unless the camera moved slightly between frames and the frames were realigned when stacked.

LENR can be avoided for every shot by turning it off and taking your own dark frame which you can apply to multiple images during PP.

--
Bruce
You learn something new every time you press the shutter
 
Last edited:
kkardster said:
alcelc said:
If long shutter must be used, hot pixel would more or less a problem never go away. Long Exposure NR could minimized the effect of the problem or using PP photo stacking to the similar effect (If I am not wrong, unlike normal NR, Long Exposure NR should act like PP photo stacking to exclude the noise and hot pixel.) Regarding your original sample, the hot pixel was actually not that serious considering a 1 minute exposure.
Click to expand...
Photo stacking likely wouldn't result in removal of hot pixels unless the camera moved slightly between frames and the frames were realigned when stacked.

LENR can be avoided for every shot by turning it off and taking your own dark frame which you can apply to multiple images during PP.
Click to expand...
 
alcelc said:
kkardster said:
alcelc said:
If long shutter must be used, hot pixel would more or less a problem never go away. Long Exposure NR could minimized the effect of the problem or using PP photo stacking to the similar effect (If I am not wrong, unlike normal NR, Long Exposure NR should act like PP photo stacking to exclude the noise and hot pixel.) Regarding your original sample, the hot pixel was actually not that serious considering a 1 minute exposure.
Click to expand...
Photo stacking likely wouldn't result in removal of hot pixels unless the camera moved slightly between frames and the frames were realigned when stacked.

LENR can be avoided for every shot by turning it off and taking your own dark frame which you can apply to multiple images during PP.
Click to expand...
Click to expand...
 
kkardster said:
alcelc said:
kkardster said:
alcelc said:
If long shutter must be used, hot pixel would more or less a problem never go away. Long Exposure NR could minimized the effect of the problem or using PP photo stacking to the similar effect (If I am not wrong, unlike normal NR, Long Exposure NR should act like PP photo stacking to exclude the noise and hot pixel.) Regarding your original sample, the hot pixel was actually not that serious considering a 1 minute exposure.
Click to expand...
Photo stacking likely wouldn't result in removal of hot pixels unless the camera moved slightly between frames and the frames were realigned when stacked.

LENR can be avoided for every shot by turning it off and taking your own dark frame which you can apply to multiple images during PP.
Click to expand...
Click to expand...
Click to expand...
 
mdobrou said:
Thank you for answers!

I should have provided better example. My concern was not exactly about photos with lens cap closed. But more about long exposure photos, even with "noise reduction" enabled.

Noise reduction "clears" hot pixels from photo and it has to put something there instead of cleared hot pixels.
So color of such pixels is computed from pixels around.
So places with hot pixels may be less sharp etc.
So more hot pixels results in slightly lower quality of photo.

So I wondered if count of hot pixels of my LX100 is usual.
Click to expand...
My Panasonic made another exposure with the shutter closed for the same time.

Then used that exposure to cancel out these heat induced abnormalities.

This will not effect the detail of the image.

If taking a minute long exposure it does i have to wait a full minute before i can view the image.
 
Don't worry. The hot pixels are normal, and any decent photo editing software (from Capture One, my favorite, to Lightroom and many others) are able to remove them without even you having to really ask.
 
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