Comparison of M.Zuiko Digital ED 12-45mm F4.0 PRO and Pentax 20-40mm ƒ/2.8-4 ED Limited DC WR HD DA

Attribute	Pentax 20-40mm ƒ/2.8-4 ED Limited DC WR HD DA ×	M.Zuiko Digital ED 12-45mm F4.0 PRO ×
Notes	HD coating, SP (Super Protect) coating; Weather-resistant construction	Dustproof and splashproof construction (IPX1 rating)
Aperture (f)	2.80 - 32.00	4.00 - 22.00
Magnification Ratio (x)	0.2	0.25
Filter Size (mm)	55	58
35mm Equivalent	-	24 - 90mm
Type	Standard Zoom	Standard Zoom
Diaphragm Blades	9	7
Zoom System	Rotary	Rotary
Image Circle	APS-C	Micro Four-Thirds
Focal Length (mm)	20.00 - 40.00	12.00 - 45.00
Brand	Pentax	Olympus
Name	Pentax 20-40mm ƒ/2.8-4 ED Limited DC WR HD DA	M.Zuiko Digital ED 12-45mm F4.0 PRO
Weight (g)	283	254
Diaphragm Blades Type	rounded	rounded
Lens Construction	9 elements in 8 groups, including 1 ED and 1 SLD element	12 elements in 9 groups, including 2 HR lenses, 1 DSA lens, 1 Super HR lens, 2 Aspherical lenses, 2 ED elements
Diagonal Angle of View (degree)	39.00 - 70.00	27.00 - 84.00
Focus Details	Quick-shift Focus; DC focus motor	High-speed Imager AF (MSC)
Diameter (mm)	71	63.4
Length (mm)	68.5	70
APS Equivalent	30.5 - 61.5mm	-
Closest Focus (m)	0.28	0.12