The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 30mm F1.4 DC HSM and the Tamron SP 35mm F1.4 Di USD for their suitability to various photography scenarios:
Size and Weight Comparison
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 F1.4 DC HSM weighs 435g, which means it is 370g (45%) lighter than the Tamron SP 35mm F1.4 Di USD which has a weight of 805g.
Filter Threads
The Sigma 30mm F1.4 DC HSM has a filter size of 62mm whereas the Tamron SP 35mm F1.4 Di USD has a 72mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 62mm filters that we recommend you to consider for the Sigma 30mm F1.4 DC HSM:
And these are the 72mm filters that we recommend for the Tamron SP 35mm F1.4 Di USD:
Lens Mounts
The Sigma 30mm F1.4 DC HSM has the Nikon F (DX) lens mount whereas the Tamron SP 35mm F1.4 Di USD has the Nikon F (FX) lens mount. Some of the latest released cameras that are compatible with these mounts are Nikon D3500, Nikon D7500 and Nikon D5600 for the Nikon F (DX) Mount and Nikon D6, Nikon D780 and Nikon D3500 for the Nikon F (FX) Mount.
Sigma 30mm F1.4 DC HSM is also available in Canon EF and Sigma SA mounts.
Tamron SP 35mm F1.4 Di USD is also available in Canon EF mount.
Focal Range
Sigma 30mm F1.4 DC HSM 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.
On the other hand, the Tamron SP 35mm F1.4 Di USD is a prime lens with fixed focal lenght of 35mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 52.5mm.