Zeiss Ultra Prime 10mm T2.1 vs Zeiss Ultra Prime 20mm T1.9

Zeiss Ultra Prime 10mm T2.1 vs Zeiss Ultra Prime 20mm T1.9

When comparing Zeiss Ultra Prime 20mm T1.9 and Zeiss Ultra Prime 10mm T2.1, which one is better?

1. Largest Aperture Comparison

The Zeiss Ultra Prime 20mm T1.9 has the largest aperture of the two lenses at 1.9 compared to the 2.1 aperture of Zeiss Ultra Prime 10mm T2.1. This means that you get more light to your sensor using Zeiss Ultra Prime 20mm T1.9 wide open, and therefore it might be a better lens in dark situations.

Winner: Zeiss Ultra Prime 20mm T1.9

Regarding largest aperture: A lower aperture number means that the widest aperture on the lens is larger. This means that more light will hit the sensor and also that the depth of field will be shallower, better separating your subject from the background.

Specifications

Full specifications table of Zeiss Ultra Prime 10mm T2.1 and Zeiss Ultra Prime 20mm T1.9:

	Zeiss Ultra Prime 10mm T2.1	Zeiss Ultra Prime 20mm T1.9
	Price ➔	Price ➔
Brand	Zeiss	Zeiss
Focal Length	10 mm	20 mm
Largest Aperture	2.1	1.9
Type	Prime	Missing