How Do I Measure Noise Using Photoshop? And What Is A Significant Change?

Started 2 months ago | Discussions thread
FingerPainter Veteran Member • Posts: 8,358
Re: Incorrection

Currantos wrote:

Since most of the noise is in the light you capture, this proposed method won't show you most of the noise of a typical photograph.. It will only show you the small portion of noise that is added by the camera.

Not sure what you mean "noise in the light"?

Shot noise, which you appear to agree does exist.

Noise is only a property of the imaging system.

There is variation in light before the imaging system. Are you tryign to draw a disticntion between variation and noise?

It is not a property of the original object being imaged.

It is a property of the light being reflected or emitted by the object begin imaged.

There can be variations in value of the object being imaged but that is not noise.

What do you call it?

Look at the black sky. Do you see bright noise, the white pixels? These are not noise, they are stars. That is what the astroguys are trying to take pictures of. Now take a look at their pictures. You will see both stars, the original "variations in the object" and the superimposed noise of the photo equipment.

Most of the noise in a typical photo is a manifestation of the variation in arrival rates and coulors of photons, not variation added by the camera.

To summarize. ALL of the noise in the photograph is from the camera(lens/sensor/etc). None is from the "light" that comes in.

Exactly incorrect. Most of the noise in a typical digital photo is due to variation present in the light even before it was captured by the camera.

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