Comparison of Olympus 7-14mm ƒ/2.8 Pro M.Zuiko Digital ED and Sigma 4.5mm f/2.8 EX DC Circular Fisheye HSM

Attribute	Olympus 7-14mm ƒ/2.8 Pro M.Zuiko Digital ED ×	Sigma 4.5mm f/2.8 EX DC Circular Fisheye HSM ×
Diagonal Angle of View (degree)	75.00 - 114.00	180.00
Aperture (f)	2.80 - 22.00	2.80 - 22.00
Diaphragm Blades Type	circular	-
Magnification Ratio (x)	0.11	0.17
Notes	Weather sealed; Fixed lens hood and pinch-style lens cap LC-79 included.	Available AF Mounts: Canon, Nikon, Pentax, Sigma, Sony; Included Accessories: Gelatin Filter Holder, Padded Case
APS Equivalent	-	1.5x: 6.8mm; 1.6x: 7.2mm
Closest Focus (m)	0.2	0.14
Focal Length (mm)	7.00 - 14.00	4.50
Diaphragm Blades	7	6
Brand	Olympus	Sigma
Image Circle	Image Circle	APS-C
Name	Olympus 7-14mm ƒ/2.8 Pro M.Zuiko Digital ED	Sigma 4.5mm f/2.8 EX DC Circular Fisheye HSM
Weight (g)	534	470
Type	Wide Zoom	Wide Prime
Zoom System	Rotary	-
Lens Construction	14 elements in 11 groups, including 2 aspherical ED, 1 double-sided aspherical, 1 aspherical, 3 Super ED , 1 ED and 2 HR elements	13 Elements in 9 Groups
Diameter (mm)	78.9	76.2
Length (mm)	105.8	77.8
Focus Details	-	Internal; HSM with full-time manual focus override
35mm Equivalent	14 - 28mm	-