Noise?

Can someone please explain what is meant by the terms luminant and chromatic noise in relation to taking pictures? Why do I want want to reduce it?

Thanks for any answers.

luminance noise means the noise is black and white.
chrominance noise means the noise is various random colors...ones I seee sometimes include red, green, yellow, blue, and so on.

reducing noise in the chrominance version generally gives the picture a smoother, less distracting feel. At higher ISO sensitivities cameras generate more noise, and the more chrominance noise you have, the more it will generally detract from the image. There are times where noise is helpful artistically though. Only you can make the determination as to where that line is.

Luminance noise looks less obtrusive and gives the image a sort of grainy feel. Sometimes people add this noise to black and white shots or convert high ISO shots to black and white to give it the feel of old black and white films which had higher sensitivities.

Different cameras render noise differently and generally can have variations in rendition between different sensitivities and different settings. Unless you are intentionally trying to generate noise in the photo, or must have another effect that requires the higher ISO sensitivity, most people advise reducing the ISO setting to as low as you can manage to get the shot with. It is easier to add noise in post processing than it is to effectively manage levels in camera. Noise reduction removes detail, and oftentimes the noise at higher ISOs can lead to detail destruction in the image on its own.

Thank you deckcadet, that was a very helpful explanation.

glad I could be of help. I wish I had some shots to show you with examples but that would take a lot of time.