Hi everyone, I need some help with taking fisheye images.

I'm currently using a Raynox DCR-FE180PRO converter with a Canon Powershot A700 series. The issue is that the images I take do not have a FULL CIRCULAR fish eye output which I require for my research - the top and bottom parts of the circles (i.e. top and bottom chords) are cropped off.

Apart from digitally modifying the images, is there any other solution for me to get a full circular image? I need a 180 degrees sky view...

Thanks so much in advance.