awenderoff

What exactly is noise reduction?

twice_shooter

twice_shooter

camerapapi Loc: Miami, Fl.

Those links are very useful to understand what noise is and how to control it. Exposing to the right (Google it) offers a decent solution to the problem of noise.
There are very good noise reduction softwares available. I use Topaz Denoise AI.

awenderoff

very helpful, thanks much!

bleirer

Noise reduction can start with the camera, even with the choice of camera. While shooting, though, be mindful that Under exposure is something that leads to noise. By that I mean shutter speed and aperture. Try to keep the ISO as close to native as possible given the shooting conditions. ISO doesn't cause noise, but it can cause underexposure which can cause noise.

CHG_CANON Loc: the Windy City

A discussion specific to Lightroom, but the concepts apply to all editing software: Basics of noise processing

anotherview Loc: California

Noise in a photograph results from amplification of the light the camera sensor records. The sensor has a fixed sensitivity, called base ISO.

The processor in the camera accepts the product of ISO, Aperture, and Shutter Speed to generate exposure.

bleirer

I would disagree in part. While there are different sources of noise, noise in exposure is random variations in the number of photons that are always there, but in underexposure the 'signal' is so weak the random part is a greater part, thus the low signal to noise ratio. The Under exposure causes the noise, the higher ISO can make it better in some cameras compared to boosting in post processing. For a truly mind numbing look at the science, start this video at minute 54. You don't have to get the math to get the point, it is well beyond me. https://youtu.be/VSdUlxgpKn4
The noise lecture continues here with more practical advice and explains ISO https://youtu.be/ia9w4ZtdULs

He gives a little recipe at the end. Basically adjust the aperture and shutter speed at base ISO to get the highest exposure possible before saturation, then if there is more room raise the ISO as much as possible before saturation. Don't blow the highlights.

anotherview Loc: California

Noise here means random information always present in a signal. A camera sensor captures photons that become a signal.

The relation of good information versus random information in a signal has a name: signal to noise ratio.

From here, things become a little complicated, but knowable if put in plain terms.

Consider, for example, that if a signal becomes amplified, then so does its inherent noise.

Camera manufacturers do their darnedest to account for and filter out this amplified noise during the processing of the signal.

If you understand this description of noise in relation to a signal, then you have gone further than most writers on the subject.

I will leave it at that for now.

bleirer

You should check out those two videos I posted, It might change your mind about one or two things.