The SX50 Noise Reduction Modes and the pictures it produces.

There are three noise reduction modes, Low, Standard, and High.  The link I am providing is all of these modes at the different noise reduction levels, as well as ISO 1600 and ISO 3200.  The scene is a dimly lit room in my house.  I suggest you either download all the pictures and compare them side by side, or look at them in Smugmug in the Original Size.  That takes care of the first 6 pictures.

Picture 7 is shot in SCN in the Night Shot mode, and picture 8 is shot in Auto.

Picture 9 is shot in Aperture Priority at f/3.4 at ISO 80.  To my surprise, this camera will not go beyond 1 second Shutter Speed in Aperture Priority, no matter how dark it is.

Picture 10, 11, and 12 are shot in Shutter Priority at 2 seconds, 3.2 seconds, and 4 seconds at ISO 80.

My Conclusion.  Using the Night Shot in SCN produces really good sharp low noise results in low light.  Standard NR is less noisy than Low and on High NR the picture has less noise but also has some smearing.  The best result in my opinion is to use NR Standard and use a noise reduction program like Topaz Denoise to remove the unwanted noise.

http://kgravett.smugmug.com/gallery/26362952_wFXksg#!i=2197664379&k=Wvgqj5k