Comparison of Zeiss 18mm f/2.8 Milvus 2.8/18 and Zeiss 21mm f/2.8 Milvus 2.8/21

Attribute	Zeiss 21mm f/2.8 Milvus 2.8/21 ×	Zeiss 18mm f/2.8 Milvus 2.8/18 ×
Filter Size (mm)	82	77
Notes	Available lens mounts: Canon EF (ZE), Nikon F (ZF.2); Weather-sealed construction to protect against dust and moisture; Hood and lens caps included.	Available lens mounts: Canon EF (ZE), Nikon F (ZF.2); Weather-sealed construction to protect against dust and moisture; Hood and lens caps included.
Closest Focus (m)	0.22	0.25
Magnification Ratio (x)	0.2	0.14
Type	Wide Prime	Wide Prime
Length (mm)	92.5	90
APS Equivalent	1.5x: 31.5mm; 1.6x: 33.6mm	1.5x: 27mm; 1.6x: 28.8mm
Diagonal Angle of View (degree)	90.00	99.90
Image Circle	35mm	35mm
Focal Length (mm)	21.00	18.00
Brand	Carl-zeiss	Carl-zeiss
Name	Zeiss 21mm f/2.8 Milvus 2.8/21	Zeiss 18mm f/2.8 Milvus 2.8/18
Weight (g)	735	675
Aperture (f)	2.80 - 22.00	2.80 - 22.00
Diaphragm Blades	9	9
Diaphragm Blades Type	rounded	rounded
Lens Construction	16 elements in 13 groups, including 4 Anomalous Partial Dispersion elements; Enhanced Zeiss T* anti-reflective coating	14 elements in 12 groups, including 4 Anomalous Partial Dispersion and 2 aspherical elements; Enhanced Zeiss T* anti-reflective coating
Diameter (mm)	95.3	102.3
Focus Details	Manual focus only	Manual focus only