The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 30mm F1.4 EX DC HSM and the Pentax DA 55mm F1.4 SDM 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. Pentax DA 55mm F1.4 SDM is the longer of the two lenses at 66mm. The Sigma 30mm F1.4 EX DC HSM with a length of 59mm, is 7mm shorter. On the other hand, the Sigma 30mm F1.4 EX DC HSM has a larger diameter of 77mm compared to the Pentax DA 55mm F1.4 SDM's 70mm diameter.
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. Pentax DA 55mm F1.4 SDM weighs 375g, 12% (55g) lighter than the Sigma 30mm F1.4 EX DC HSM's weight of 430g.
Filter Threads
The Sigma 30mm F1.4 EX DC HSM has a filter size of 62mm whereas the Pentax DA 55mm F1.4 SDM has a 58mm 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 EX DC HSM:
And these are the 58mm filters that we recommend for the Pentax DA 55mm F1.4 SDM:
Lens Mounts
The Sigma 30mm F1.4 EX DC HSM has the Pentax KAF lens mount whereas the Pentax DA 55mm F1.4 SDM has the Pentax KAF3 lens mount. Some of the latest released cameras that are compatible with these mounts are Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF Mount and , and for the Pentax KAF3 Mount.
Sigma 30mm F1.4 EX DC HSM is also available in the Canon EF-S , Nikon F (DX), Four Thirds, Sony Alpha and Sigma SA mounts.
Focal Range
Sigma 30mm F1.4 EX 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 Pentax DA 55mm F1.4 SDM is a prime lens with fixed focal lenght of 55mm which has an effective (full-frame 35mm equivalent) focal range of 82.5mm when used on a APS-C / DX format camera.
