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AlvinLeung · Jun 7, 2007, 6:58 PM

Yea, so i would like to know why my D50 produces photos with alot of Noise?

I gets even worse when i increase the Contrast in Photoshop*

Thanks.

For these example photos, i used Nikon 50mm f1.8

JimC · Jun 7, 2007, 7:12 PM

That's not a lot of noise for ISO 1600, and noise is going to be higher as ISO speed is increased, especially indoors without a flash.

When the signal generated by the individual photosites is very weak (i.e., not much above the noise generated by other sources because not enough light is hitting them), and you amplify that signal to make the image bright enough for the aperture/shutter speed being used (which is what happens when ISO speed is increased), you also amplify the noise, too.

If you think it's objectionable at the viewing/print sizes needed, use noise reduction tools (or use a flash so that you don't need to go with ISO 1600 if you think it's an issue for your desired purposes).

Here are links to a few of the more popular tools for reducing noise:

Neat Image

Noise Ninja

Noiseware

JimC · Jun 7, 2007, 7:20 PM

P.S.

Be careful about your exposure, too - especially with a backlit subject. Those shutter speeds look pretty darn fast to me for the last couple of photos (making me wonder why you were using ISO 1600 for them and if you brightened them later with software).

If you push the image any (brighten it using software), you will see higher noise levels, just as if you used an even *higher* ISO speed.

It's best to have correct exposure to begin with. I don't know if that's would might have happened. But, for a backlit subject, you'll usually want to use a +EV setting with Exposure Compensation to make sure it's exposed bright enough to begin with if you don't use a flash for fill, so that you are not pushing the exposure later (increasing noise levels).

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Jun 7, 2007, 6:58 PM	#1
AlvinLeung Junior Member Join Date: May 2007 Posts: 6	Yea, so i would like to know why my D50 produces photos with alot of Noise? I gets even worse when i increase the Contrast in Photoshop* Thanks. For these example photos, i used Nikon 50mm f1.8

Jun 7, 2007, 7:12 PM	#2
JimC Administrator Join Date: Jun 2003 Location: Savannah, GA (USA) Posts: 22,378	That's not a lot of noise for ISO 1600, and noise is going to be higher as ISO speed is increased, especially indoors without a flash. When the signal generated by the individual photosites is very weak (i.e., not much above the noise generated by other sources because not enough light is hitting them), and you amplify that signal to make the image bright enough for the aperture/shutter speed being used (which is what happens when ISO speed is increased), you also amplify the noise, too. If you think it's objectionable at the viewing/print sizes needed, use noise reduction tools (or use a flash so that you don't need to go with ISO 1600 if you think it's an issue for your desired purposes). Here are links to a few of the more popular tools for reducing noise: Neat Image Noise Ninja Noiseware

Jun 7, 2007, 7:20 PM	#3
JimC Administrator Join Date: Jun 2003 Location: Savannah, GA (USA) Posts: 22,378	P.S. Be careful about your exposure, too - especially with a backlit subject. Those shutter speeds look pretty darn fast to me for the last couple of photos (making me wonder why you were using ISO 1600 for them and if you brightened them later with software). If you push the image any (brighten it using software), you will see higher noise levels, just as if you used an even higher ISO speed. It's best to have correct exposure to begin with. I don't know if that's would might have happened. But, for a backlit subject, you'll usually want to use a +EV setting with Exposure Compensation to make sure it's exposed bright enough to begin with if you don't use a flash for fill, so that you are not pushing the exposure later (increasing noise levels).