Well, the raw won't be a circle, I think. Some Fisheye lenses just have bent edges, but the aspect ratio would still be normal, like it would still be 3:2 and fill the screen of your editor, it would just have bent up edges. The photo above is a circle with black edges like looking through a hole.
Or am I crazy and all fisheye lenses are circular and some people just crop in to the circle? But I have heard people say circular fisheye and non circular fisheye, what the heck, are all fisheye lenses circular? I've never owned one.
Yes, so your lens is definitely a circular fisheye. I prefer one that just does bent edges, no black circle around the photo. I'm looking to go cheap too because I have heard that shooting fisheye can get boring fast and you have a tendency to use them very little.