Comparison of Canon EF 8-15mm ƒ/4L USM Fisheye and Pentax SMC P-DA Fish-Eye 10-17mm f/3.5-4.5 ED IF

Attribute	Canon EF 8-15mm ƒ/4L USM Fisheye ×	Pentax SMC P-DA Fish-Eye 10-17mm f/3.5-4.5 ED IF ×
Diagonal Angle of View (degree)	175.50 - 180.00	100.00 - 180.00
Notes	Included Accessories: lens hood, case	Distance scale, Integrated lens hood; no filter ring or rear-element filter clip
Aperture (f)	4.00 - 22.00	3.50 - 32.00
Closest Focus (m)	0.16	0.14
Magnification Ratio (x)	0.39	0.39
Type	Wide Zoom Fisheye	Fisheye Zoom
Focus Details	Inner focusing; Ultra-sonic Motor (USM) with AF/MF switch	"Quick-Shift" Focus System for instant shift to manual focus
APS Equivalent	13 - 24mm	15 - 25.5mm
Diaphragm Blades	7	6
Image Circle	35mm	APS-C
Focal Length (mm)	8.00 - 15.00	10.00 - 17.00
Brand	Canon	Pentax
Name	Canon EF 8-15mm ƒ/4L USM Fisheye	Pentax SMC P-DA Fish-Eye 10-17mm f/3.5-4.5 ED IF
Weight (g)	540	320
Zoom System	Rotary	Rotary
Length (mm)	83	71.5
Diameter (mm)	78.5	68
Lens Construction	14 elements in 11 groups, including UD and aspherical elements	10 elements in 8 groups