ON TRIAL FUJINON
As we've noted many times, it's with lenses that the cropped sensor formats deliver the most obvious savings in size and weight. And this is particularly true at either extreme of the focal length range – supertelephotos and ultra wide-angles. Typically, an ultra-wide lens has an angle-of-view of 90 degrees or wider and, on a full frame sensor, this requires a large-diameter front element… which is also heavy and expensive plus a number of elements to perform the optical rectilinear correction. Ultra-wide zooms can be even bulkier although the mirrorless camera configuration – with its shorter back focus distance – means that the total number of elements can be less because less optical correction is required.
Nevertheless, there's still a lot of differences in the size and weight between and a zoom and a prime, as illustrated by comparing Fujifilm's new X mount 8mm f/3.5 prime with the existing 8-16mm f/2.8 zoom. Yes, the latter is slightly faster and maintaining f/2.8 throughout the zooming range adds to the complexity of the optical design, but this is a big lens even by ‘APS-C’ format standards. It weighs in at 805 grams – versus the 8mm's 215 grams – and is
