This was shot with my Pentax K2000 and a Pentax DAL 18-55mm WP lens (set to 24mm) with a fish-eye filter attachment.
The "Fish-Eye" filter attachment screws onto the filter ring.
The filter attachment is a vintage Heath/ Zenith 52mm screw-on filter that reduces the focal length by 1/2.
Essentially reducing the 24mm setting to 12mm. (@18mm the image essentially becomes a pin hole.
It is one half of a kit that includes a 4 times telephoto attachment.
My Jeep loves to go camping and when it is being towed behind the RV, it is very happy... as you can see here.
It's all on how you look at it...