Is this what we call noise?

[nüborn]

On a 20 secs exposure at 400 ISO, I ended up with some grain but also very bright sparks randomly colored. Is this normal? Is this what we call noise?

Now, I just saw that there some options turned on (to reduce the noise actually) in the setup of my Canon camera, would that happen to be the reason why I get these colored dots?
Long exposure noise reduction 1:Auto
High ISO speed noise reduction 1:On
Highlight tone priority 0isable

 

[pbelarge]

That looks like it may be dust. There is noise in the photo, take a look at the photo at 100% and you will see it more readily.

 

[haynchinook334]

Looks like your lens/sensor might be dirty.

 

[sleist]

If I'm reading your mind correctly, the "grain" you are referring to is the noise.

 

[LaFoto]

Those dots look like dead pixels to me, more than dust. And your photo is not noisy (translated into film-lingo: it has no grain). Noise in the world of digital photography is what grain is in the world of film photography.

 

[Phranquey]

Those dots look like dead pixels to me, more than dust. And your photo is not noisy (translated into film-lingo: it has no grain). Noise in the world of digital photography is what grain is in the world of film photography.

:thumbup:

Shoot a bright white background, and any dust on your sensor becomes clearly evident as little grey blurs... but usually aren't seen on darker backgrounds like this. Those little "hotspots", particularly the ones on the right, are burned out pixels in your sensor.

 

[nüborn]

Thanks folks. Turned out that they are "hot pixels". Can only see them in very very long exposures.

 

[Derrel]

Those are stuck-on pixels or "hot pixels", which often show up in long exposures.

 

[ghache]

hot pixels sucks!

 

[Dao]

Agree. Looks like Hot pixels

 

[Big Mike]

What you have here are hot pixels.

HERE is an example of digital noise.

Dust on the sensor