The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 50mm F1.4 EX DG HSM and the Olympus 17.5-45mm f3.5-5.6 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. Olympus 17.5-45mm f3.5-5.6 is the longer of the two lenses at 70mm. The Sigma 50mm F1.4 EX DG HSM with a length of 68mm, is 2mm shorter. On the other hand, the Sigma 50mm F1.4 EX DG HSM has a larger diameter of 85mm compared to the Olympus 17.5-45mm f3.5-5.6's 71mm 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. Olympus 17.5-45mm f3.5-5.6 weighs 210g, 58% (295g) lighter than the Sigma 50mm F1.4 EX DG HSM's weight of 505g.
Filter Threads
The Sigma 50mm F1.4 EX DG HSM has a filter size of 77mm whereas the Olympus 17.5-45mm f3.5-5.6 has a 52mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 77mm filters that we recommend you to consider for the Sigma 50mm F1.4 EX DG HSM:
And these are the 52mm filters that we recommend for the Olympus 17.5-45mm f3.5-5.6:
Lens Mounts
Both the Sigma 50mm F1.4 EX DG HSM and the Olympus 17.5-45mm f3.5-5.6 has the same Four Thirds lens mount. Some of the latest released cameras that are compatible with the Four Thirds lenses are Olympus E-5, Olympus E-600 and Olympus E-620.
Sigma 50mm F1.4 EX DG HSM is also available in the Canon EF , Pentax KAF3, Sony Alpha, Sigma SA and Nikon F (FX) mounts.
Focal Range
Sigma 50mm F1.4 EX DG HSM is a prime lens with fixed focal lenght of 50mm.
On the other hand, the Olympus 17.5-45mm f3.5-5.6 has a focal range of 18-45mm and 2.5X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 36-90mm when used on a FourThirds format camera.
