Comparison of Nikon 180-400mm f/4E TC1.4 FL ED VR Nikkor and Pentax SMC P-FA 250-600mm f/5.6 ED IF

Attribute	Pentax SMC P-FA 250-600mm f/5.6 ED IF ×	Nikon 180-400mm f/4E TC1.4 FL ED VR Nikkor ×
Filter Size (mm)	43	5
Closest Focus (m)	3.5	2
Magnification Ratio (x)	0.2	0.25
Length (mm)	442	362.5
Focus Details	Internal	Internal SWM (AF-S); AF Recall Mode; Focus Range Limiter (2m to infinity (Full) or 6m to infinity); A/M, M/A, M Mode Switch
Diaphragm Blades Type	-	rounded
Zoom System	Rotary with lock	Rotary
Image Circle	35mm	35mm
Focal Length (mm)	250.00 - 600.00	180.00 - 400.00
Name	Pentax SMC P-FA 250-600mm f/5.6 ED IF	Nikon 180-400mm f/4E TC1.4 FL ED VR Nikkor
Brand	Pentax	Nikon
Weight (g)	5049	3500
Type	Telephoto Zoom	Telephoto Zoom
Lens Construction	18 elements in 16 groups, including 1 ED element	27 elements in 19 groups, including 1 Fluorite element and 8 ED elements; Nano Crystal Coat; Super Integrated Coating
Notes	-	Built-in 1.4x Teleconverter; VR Image Stabilization up to 4 stops; Sealed against dust and moisture.
APS Equivalent	375 - 900mm	270 - 600mm (378 - 840mm with built-in TC engaged)
Aperture (f)	5.60 - 32.00	4.00 - 45.00
Diaphragm Blades	-	9
Diagonal Angle of View (degree)	4.10 - 9.90	6.20 - 13.40
Diameter (mm)	71	128