Comparison of Pentax 15mm ƒ/4 ED AL Limited SMC DA and Pentax SMC P-FA 20mm f/2.8

Attribute	Pentax SMC P-FA 20mm f/2.8 ×	Pentax 15mm ƒ/4 ED AL Limited SMC DA ×
Name	Pentax SMC P-FA 20mm f/2.8	Pentax 15mm ƒ/4 ED AL Limited SMC DA
Image Circle	35mm	APS-C
Brand	Pentax	Pentax
APS Equivalent	30mm	23mm
Focal Length (mm)	20.00	15.00
Diagonal Angle of View (degree)	94.00	86.00
Diaphragm Blades	-	7
Closest Focus (m)	0.24	0.18
Focus Details	-	Internal, with "Quick-Shift" focus system
Filter Size (mm)	67	49
Magnification Ratio (x)	0.12	0.15
Notes	-	Hood is built-in, pullout type
Aperture (f)	2.80 - 22.00	4.00 - 22.00
Length (mm)	44	39.5
Weight (g)	255	212
Lens Construction	10 elements in 9 groups	8 elements in 6 groups
Type	Wide Prime	Wide Prime
Diameter (mm)	70	63