Comments about Vivitar Vivitar Series 1 0.43x Wide Angle Auxiliary Lens with 58mm Mounting Thread:

I bought this knowing that it would not make my 18mm lens a fisheye. However, the quality I got out of it is so bad that the picture is not even worth taking the time to process in camera raw (it is that bad). It is distorted (all of it, not just the borders), it makes it look out of focus, but it isn't, it is just.. weird, it sucks. There's also really bad chromatic aberrations as you move away from the center.
I didn't buy the zoom attachment cause I could tell from the sample picture that it was bad, but I never thought this one could suck so much too...
You can see in the picture I attach that all detail is gone. It looks like there was no light, which is not true, I was shooting <1/300s