Why is Nikon video poorer in quality than Canon?

I was recently helping a guy get some better camera angles at a live performance in a record store, and I have a Nikon d5100 and he has a Canon crop-sensor camera, but I can't remember what it was called. There was not a lot of light available. He had an 85mm 2.0 and I had a 35mm 1, 8. We both shot at 30fps 1080p and similar exposure.

But his video looked almost perfectly clean while mine had noticeable noise. I don't know if he's going to be able to use it. Why is this the case for video? According to DXOmark, the Nikon d5100 has the best low light ISO capability of any APS-C camera except 1 Pentax one and most of the Canon ones are much less capable, so it must be exclusively a video thing.

Added (1). My lens was not stopped down, it was at 1.8. Also, when I said 30fps, what I meant to say was shutter speed of 30, 25fps.

I'm looking back over the video comparisons and it's not actually as different as I remember, but it is still there.

Added (2). As for what my ISO was set to, I can't say because on the d5100, the ISO setting doesn't affect live view at all, which is always set to auto-ISO, but I had my exposure set to -0.3 to give the right lowish lighting look and all my settings locked in manual.

There's more to shooting video than the equipment.

Technique is important buy setting up the camera so that you are shooting at the lowest ISO possible is also important.

My guess is that you had your lens stopped down and your fine camera had to auto adjust the ISO to get ANY exposure.

Here is a video shot with the Nikon D7000 (similar sensor performance to your D5100)

You know, you can buy high quality cameras, but you can't buy experience.

Spend some time learning how to use your camera and soon you too will be able to produce decent videos using a camera designed to shoot stills but has a video "feature"

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