ISO noise

Did you nail the exposure in camera or did you have to adjust it in pp? unless you nail itin camera they will be noisey.
 
Noise will also tend to show up in longer exposures (sensor gets "hot" in a long exposure) also noise is a lot more visible in the darker sections.
 
Wigster said:
Noise will also tend to show up in longer exposures (sensor gots "hot" in a long exposure) also noise is a lot more visible in the darker sections.
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that is good advice
 
Levidog said:
Why is it that sometimes I get iso noise and sometimes not. I was shooting in murky conditions this afternoon at 640 and it came out too grainy to use, I have used 1250 in different conditions with vitually no grain at all.

Sean
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Indeed, if you under expose just so much as a smidgeon at higher ISO values you'll get notably more noise. Generally speaking, an under exposure with an exposure tweak in post will produce a much noisier result.

Luminance and colour noise are much more notable in shadow or darker areas of the frame too, so a well exposed shot on a bright day outdoors for example will appear to have less noise. :thumbs:
 
Jaffster said:
Sensor gets hot?!

I take exposures lasting 100's of seconds and have never experienced anything like this.
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It's certainly not hot on a natural detecable scale by humans, but at the sub level it's true.

You will certainly not feel the sensor "hot" or even warm, just a very slight change within the sensor itself, better described below:

"
The photons collected by the photosites on the sensor are converted to electrons.
The sensor generates heat.
The heat produces anomalous electrons.
The camera converts them into image data along with the electrons created by photons.
This noise is called dark noise or dark current noise."
 
Very interesting question, and very informative answers.:thumbs:
 
So if noise appears in under-exposed pictures more, would it be better to "shoot to the right" (I think that's what it's called) when having to use high ISO's such as sports?

Or would the noise just come back when you bring the exposure down in PP?
 
Are you using Active D-Lighting? Try turning it off if you are as this was doing silly things for me unless running at really low ISO.
 
There's a lot of advise on the web regards shoot to the right (right means to the right of the histogram which is the highlight side). Look at your histogram and shoot so that the pixels are just about touching the right hand side but not clipping the highlights.

You should get less noise shooting this way but each scene is different and it may not always work!

Experience will teach you
 
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