Comparison of Pentax SMC P-FA 250-600mm f/5.6 ED IF and Sigma APO 800mm f/5.6 EX DG HSM

Attribute	Sigma APO 800mm f/5.6 EX DG HSM ×	Pentax SMC P-FA 250-600mm f/5.6 ED IF ×
Aperture (f)	5.60 - 32.00	5.60 - 32.00
Diagonal Angle of View (degree)	3.10	4.10 - 9.90
Magnification Ratio (x)	0.11	0.2
Filter Size (mm)	46	43
Type	Telephoto Prime	Telephoto Zoom
Closest Focus (m)	7	3.5
APS Equivalent	1.5x: 1200mm; 1.6x: 1280mm	375 - 900mm
Diaphragm Blades	9	-
Image Circle	35mm	35mm
Focal Length (mm)	800.00	250.00 - 600.00
Brand	Sigma	Pentax
Name	Sigma APO 800mm f/5.6 EX DG HSM	Pentax SMC P-FA 250-600mm f/5.6 ED IF
Weight (g)	4740	5049
Zoom System	-	Rotary with lock
Lens Construction	13 elements in 10 groups, including 2 ELD elements	18 elements in 16 groups, including 1 ED element
Diameter (mm)	156.5	71
Length (mm)	520	442
Notes	Available AF Mounts: [HSM version]: Sigma, Canon, Nikon; [w/o HSM]: Minolta, Pentax	-
Focus Details	Internal; HSM with full-time manual override	Internal