The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Voigtlander Nokton 25mm F0.95 Type II and the Sigma 30mm F2.8 EX DN for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is a crucial factor to consider when comparing two lenses. Voigtlander Nokton 25mm F0.95 Type II is the longer of the two lenses at 70mm. The Sigma 30mm F2.8 EX DN with a length of 39mm, is 31mm shorter. On the other hand, there is no difference between the max diameters of these lenses, both coming at 61mm.
The weight of a lens is equally significant as its external dimensions, particularly if you intend to handhold your camera and lens combination for extended periods. Sigma 30mm F2.8 EX DN weighs 135g, 68% (300g) lighter than the Voigtlander Nokton 25mm F0.95 Type II's weight of 435g.
Filter Threads
The Voigtlander Nokton 25mm F0.95 Type II has a filter size of 52mm whereas the Sigma 30mm F2.8 EX DN has a 46mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 52mm filters that we recommend you to consider for the Voigtlander Nokton 25mm F0.95 Type II:
And these are the 46mm filters that we recommend for the Sigma 30mm F2.8 EX DN:
Lens Mounts
Both the Voigtlander Nokton 25mm F0.95 Type II and the Sigma 30mm F2.8 EX DN has the same Micro Four Thirds lens mount. Some of the latest released cameras that are compatible with the Micro Four Thirds lenses are OM System OM-1 II, Panasonic G9 II and OM System OM-5.
Sigma 30mm F2.8 EX DN is also available in Sony E mount.
Focal Range
Voigtlander Nokton 25mm F0.95 Type II is a prime lens with fixed focal lenght of 25mm which has an effective (full-frame 35mm equivalent) focal range of
50mm when used on a FourThirds format camera.
On the other hand, the Sigma 30mm F2.8 EX DN is a prime lens with fixed focal lenght of 30mm which has an effective (full-frame 35mm equivalent) focal range of 45mm when used on a APS-C / DX format camera.