The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 85mm F1.4 DG HSM and the Sigma 800mm F5.6 EX DG HSM 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. Sigma 800mm F5.6 EX DG HSM is the longer of the two lenses at 521mm. The Sigma 85mm F1.4 DG HSM with a length of 126mm, is 395mm shorter. Besides being longer, the Sigma 800mm F5.6 EX DG HSM also has a larger diameter of 157mm compared to the Sigma 85mm F1.4 DG HSM's 95mm 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. Sigma 85mm F1.4 DG HSM weighs 1130g, which means it is 3770g (76%) lighter than the Sigma 800mm F5.6 EX DG HSM which has a weight of 4900g.
Filter Threads
The Sigma 85mm F1.4 DG HSM has a filter size of 86mm whereas the Sigma 800mm F5.6 EX DG HSM 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 86mm filters that we recommend you to consider for the Sigma 85mm F1.4 DG HSM:
And these are the 46mm filters that we recommend for the Sigma 800mm F5.6 EX DG HSM:
Lens Mounts
Both the Sigma 85mm F1.4 DG HSM and the Sigma 800mm F5.6 EX DG HSM has the same Sigma SA lens mount. Some of the latest released cameras that are compatible with the Sigma SA lenses are Sigma Quattro, Sigma Quattro H and Sigma SD1 Merrill.
Sigma 85mm F1.4 DG HSM is also available in Nikon F (FX) and Canon EF mounts.
Sigma 800mm F5.6 EX DG HSM is also available in Canon EF and Nikon F (FX) mounts.
Focal Range
Sigma 85mm F1.4 DG HSM is a prime lens with fixed focal lenght of 85mm.
On the other hand, the Sigma 800mm F5.6 EX DG HSM is a prime lens with fixed focal lenght of 800mm.