I have a Nikon D50. It's about 5 years old now, I think, and Nikon doesn't make it anymore. I have always had really bad noise problems with it but I've always blamed my photography skills. Unfortunately, the more I learn the worse the noise seems to get. I took pictures of my grandma's wedding yesterday and there is so much noise in the pictures... I know they aren't the very best pics and my camera isn't the best quality, but I don't feel like the noise should be so obvious at low ISOs.

Is there something wrong with my camera or something wrong with my photography? Here's a SOOC shot to illustrate. You can see the noise in the blacks and if I lighten the picture at all it is really noticeable.

Exposure: 1/125
Aperture: f/4.0
ISO: 400