... Journal Entry
Despite the continued development of zoom lenses and the optical marvels they have become with the advancement in glass technology, CAD design and firmware correction of aberrations, to provide high performance, faster aperture optics, there comes a time when only that life long friend the fast prime lens will do.
In the world of 35mm film photography one of my favourite lenses and indeed often the only lens I will on many occasions carry attached to my camera is a fast 35mm f1.4 prime. Throughout my lifetime of photographic peregrinations it is the one optic I have used by default with which to make a vast number of my pictures. A reasonably close second has been a similarly fast 85mm lens.
In the digital world I have now standardised on the APS-C format with my X-T50 so with its 1.5x crop factor I have a 23mm f1.4 as the equivalent to my 35mm f1.4 in the film world and similarly a 56mm f1.4 equivalent to my 85mm f1.4 film camera lens.
So let's start with the definition of a fast prime: A fast prime lens is a fixed focal length (non-zooming) optic with a large (fast) open aperture of typically f1.4. As well as being faster, these lenses usually have the welcome attributes of being smaller plus more affordable whilst providing higher image quality than the nearest equivalent zoom, all else being equal. They also, by virtue of their wider apertures providing shallow depth of field, allowing for pictures with excellent subject separation to be created.
Now there are few faster primes out there with apertures of f1.1, f1.0 and f0.95 often referred to as super fast primes. I have had the opportunity to try out a number of these lenses over the years and they all had three things in common: enormous weight/bulk, wafer thin depth of field wide open, and eye watering expense, non of which endeared them to me. It is probably why they are often referred to as exotic lenses.
Fast apertures in low light allows me to keep the ISO as low as possible for maximise picture quality and recorded detail as does the quality of top notch prime lenses even when used wide open at f1.4. Indeed they beg to be used in such a manner as illustrated in all of the pictures in this article all taken this way on my Fujinon XF 23mm f1.4 R LM WR (35mm crop factor equivalent).
Using a fixed focal length lens, i.e. with no zoom, gives you a big advantage and also a big dis-advantage - it just depends. In an environment where you can move about freely, you can typically get much sharper images at much wider apertures than with a zoom lens. However in an environment where movement is constrained, a zoom lens gives you the flexibility to control the framing of the subject and its relative perspective too from the same spot.
Fast primes are also much lighter and less bulky than an equivalent fast f2.8 pro zoom whose zoom range includes that of the prime you are using not to mention normally substantially cheaper..
The world is however changing. There are emerging zoom lenses with the latest optical technology that are of excellent quality rivalling that of primes and lately have become speedier with an open aperture of f2, at a big cost of course. But...
... there's just something about a fast glass prime that sings to me... 😀. They still can't be beaten.