Comparing the Sigma lenses; 10-20 uwa zoom to the 15mm fisheye and the 14mm rectalinear:

The Sigma 10-20mm ex 4-5.6 is on the left; the Sigma 15mm 2.8 ex fisheye in the middle and the Sigma 14mm 3.5 Rectal is on the right.

Note The 1020 was set on 15mm, also the 14mm was shot on a different day with slightly different light, tho about the same time, and at low tide as you can see.

Normal blanket processing done on all images.