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11-25-2009, 07:36 PM   #1
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Weird noise on the underexposed part of the subject

Sorry if this question has been asked before.
Iím relatively new to photography and may not know exactly what Iím doing (one of those guys who gets a couple of keepers out of thousand less-than-mediocre shots).

I just tried wireless flash and noticed an interesting issue. Non exposed, or rather, underexposed portion of the subject has some strange ďdigitalĒ noise.

Here is the shot of my subject Kiwi:


This was one of the first shots Iíve taken with the wireless flash.
Flash af-360fgx
Camera: K20D
ISO200
75mm
F6.7
1/180 sec

Here is the 100% crop oh Kiwiís face.


Notice his right eye and fur has some weird noise. Itís like camera is trying to forcefully expose that part of the subject.
I normally shoot in jpg and wonder if there is anything I should do with the camera settings to get rid of that noise. I thought that ISO 200 should be pretty good as far as the noise level goes... hmm,..

Sorry if this is a dumb question. Iím relatively new to photography and very new to K20D. Thank you!

11-25-2009, 09:47 PM   #2
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looks pretty normal to me
11-25-2009, 11:04 PM   #3
Ash
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Even with squinting in every possible way, I cannot make out the noise you're referring to.

Be aware that noise can still occur in ISO 100 or 200 shots in the shadow areas if the shots are grossly underexposed and you've had to 'push' them in post-processing.
11-26-2009, 12:28 AM   #4
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I can see it, Its that funnty looking grain in the really dark areas.

I had this same issue when I first got my K7 thinking it was a fault with the camera. However I was quickly shown that my inexperience and noobness was the sole cause of this.

Quite simply in those areas (and the way I understand) the CMOS sensor has not received enough light to register hence why you see that, its perfectly normal.

Best solution for that is to shoot in Raw and make adjustments to the black level. This can and will happen on any camera, I was going back througn night shoots I took on my P&S from overseas and found this same thing. Also depending on how your monitor is adjusted you will see this more obviously than not.

11-26-2009, 12:50 AM   #5
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It's not visible here either.
Though it may still be visible on the original(care to share?).

It's also normal to get noise artifacts in shadow that are pulled-up in exposure and there are measures you can take to minimize this effect also.

PS. I hope your not referring to the pooky rocks in the corner of your cat's eye
11-26-2009, 04:14 AM   #6
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I think it's the cat..... try a different breed.
11-26-2009, 04:24 AM   #7
Ash
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Just saw it on a bigger screen.
Faintly obvious, but there - colour noise.
Quite expected, especially if exposure is boosted by the computer software.
Easily fixed by reducing any default exposure settings to 0 (assuming this is correct exposure for the shot you wanted).
The problem does keep surfacing when any low ISO shot is pushed and it is still expected that deep shadow areas on the images remain completely clean.
11-26-2009, 06:47 AM   #8
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QuoteOriginally posted by Ash Quote
Just saw it on a bigger screen.
Faintly obvious, but there - colour noise.
Quite expected, especially if exposure is boosted by the computer software.
Easily fixed by reducing any default exposure settings to 0 (assuming this is correct exposure for the shot you wanted).
The problem does keep surfacing when any low ISO shot is pushed and it is still expected that deep shadow areas on the images remain completely clean.
As I said it's best to shoot in RAW and tinker with the black level, best way to correct that.

11-26-2009, 07:03 AM   #9
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Thanks a lot guys! I will try changing the default exposure settings to 0. Also, I think that there is a way to remove in camera noise correction (if that has anything to do with it)Ö
If all fails I will get a different bead of cat!


On a side note.. When looking at this picture in Internet Explorer or in Firefox, noise I spoke about is completely gone. Even White balance is different. It is a bit cooler in explorer and in Firefox than when I look at it in Lightroom or Windows picture viewer.
Did anyone experience this before?

Thank you all!
11-26-2009, 09:45 AM   #10
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QuoteOriginally posted by sash Quote
Thanks a lot guys! I will try changing the default exposure settings to 0. Also, I think that there is a way to remove in camera noise correction (if that has anything to do with it)Ö
If all fails I will get a different bead of cat!


On a side note.. When looking at this picture in Internet Explorer or in Firefox, noise I spoke about is completely gone. Even White balance is different. It is a bit cooler in explorer and in Firefox than when I look at it in Lightroom or Windows picture viewer.
Did anyone experience this before?

Thank you all!
Start here ...... you'll need a coffee or maybe a scotch ....

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