Comparison of Sigma 4.5mm f/2.8 EX DC Circular Fisheye HSM and Sigma 8-16mm ƒ/4.5-5.6 DC HSM

Attribute	Sigma 4.5mm f/2.8 EX DC Circular Fisheye HSM ×	Sigma 8-16mm ƒ/4.5-5.6 DC HSM ×
Diagonal Angle of View (degree)	180.00	75.70 - 114.50
Notes	Available AF Mounts: Canon, Nikon, Pentax, Sigma, Sony; Included Accessories: Gelatin Filter Holder, Padded Case	Available AF Mounts: [HSM version]: Sigma, Canon, Nikon; [w/o HSM]: Minolta, Pentax
Aperture (f)	2.80 - 22.00	4.50 - 29.00
Closest Focus (m)	0.14	0.24
Magnification Ratio (x)	0.17	0.13
Type	Wide Prime	Ultra Wide Zoom
Focus Details	Internal; HSM with full-time manual focus override	Internal Focus; HSM with full-time manual override
APS Equivalent	1.5x: 6.8mm; 1.6x: 7.2mm	1.5x: 12 - 24mm; 1.6x: 12.8 - 25.6mm
Diaphragm Blades	6	7
Image Circle	APS-C	APS-C
Focal Length (mm)	4.50	8.00 - 16.00
Brand	Sigma	Sigma
Name	Sigma 4.5mm f/2.8 EX DC Circular Fisheye HSM	Sigma 8-16mm ƒ/4.5-5.6 DC HSM
Weight (g)	470	555
Diameter (mm)	76.2	105.7
Length (mm)	77.8	75
Zoom System	-	Rotary
Lens Construction	13 Elements in 9 Groups	15 Elements in 11 Groups, including 3 aspherical and 4 FLD elements