Comparison of Olympus 25mm f/2.8 Zuiko Digital and Pentax 40mm f/2.8 Limited HD DA

Attribute	Olympus 25mm f/2.8 Zuiko Digital ×	Pentax 40mm f/2.8 Limited HD DA ×
Diagonal Angle of View (degree)	47.00	39.00
Aperture (f)	2.80 - 22.00	2.80 - 22.00
Diaphragm Blades Type	circular	rounded
Filter Size (mm)	43	49
Notes	Included Accessories: Lens cap (LC-43), rear cap (LR-1). Screw-in aluminum lens cap, and lens hood optional.	Available in black or silver; High-grade multi-layer HD (High Definition) coating; Rounder aperture blades should yield more pleasing bokeh.
Focus Details	-	"Quick Shift" AF/MF mechanism
Type	Standard Prime	Standard Prime
Diaphragm Blades	7	9
Lens Construction	5 elements in 4 groups, including aspherical element	5 elements in 4 groups
Image Circle	Image Circle	APS-C
Focal Length (mm)	25.00	40.00
Brand	Olympus	Pentax
Name	Olympus 25mm f/2.8 Zuiko Digital	Pentax 40mm f/2.8 Limited HD DA
Weight (g)	95	89
Diameter (mm)	64	63
Length (mm)	23.5	15
35mm Equivalent	50mm	-
Magnification Ratio (x)	0.19	0.13
APS Equivalent	-	61mm
Closest Focus (m)	0.2	0.4