…Ok, so that’s a bit of a sensationalist headline. I don’t really hate it. But I’m going to offer a bit of a contriarian view on the much venerated “fast zoom” type lens. On pretty much any photgraphy fourm/discussion a question that pops up all the time is “I’m looking to upgrade from my “kit” lens, what is a good choice”. Invariably the responses will point toward the traditional “fast normal zoom”, ie a 24-70/2.8 or the like.
I, on the other hand prefer a slow zoom (high quality and still constant aperture, such as Canon’s F/4L lenses) and a fast prime.
Point 1: f/2.8 is one stop faster than f/4. In other words, the difference between bumpring your iso from 200->400 (or 400-800 etc…) Us digital photographers sometimes forget how spoiled we are… back in the day we needed every bit of speed we could get out of our glass, as film speed was often the limiting factor. Anyone remember shooting film past ASA400? got grainy pretty fast didn’t it 🙂 These days I will shoot my 5d at 3200 without even blinking. And it’s only getting better from there! Considering that an f/4 zoom is a)smaller/lighter b)greater range (24-105mm vs 24-70), I would much rather bump my iso one stop than carry the extra bulk/weight of a 2.8 zoom around all day. Not to mention that when using strobes/lights, I’m generally working at f/4-5.6 maximum, it’s only available (low) light that demands fast glass which leads me to my second point.
point 2: in my experience, when I need low light capability *i need low light capability*, and in those cases even f/2.8 won’t cut it. A f/1.4 lens gives you a *3 stop* advantage over an f/4 zoom (and 2 stops even over a 2.8!) – that’s the same as going from 200-1600ISO, not insignificant! or consider the low light potential of a 1.4 lens on one of the new bodies capable of doing ISO12,800 or even 25,600 – now we’re getting into the “EV -crazydark” territory. Not to mention that at f/2.8 the prime is already stopped down two stops, while the zoom is still wide open, which will generally give you better edge to edge quality.
Ok, so maybe I’m a bit biased, as I am a “prime guy”, but I think a lot of folks underestimate the potential of the humble fixed focal length lens. The classic 50/1.4 is a surprisingly flexible lens that can yield a huge variety of perspectives simply by taking a few steps forward or back.
Some will respond that it’s the combination of flexibility and speed that makes the 2.8 appealing, but to me it seems like you sort of get shorted on both ends – it’s not fast enough to be *really fast* and not flexible enough to preclude frequent lens switching.
(and before the hate mail starts, yes I’ve used the fast zooms plenty. Yes they are great lenses, and yes, maybe if I were a dedicated wedding shooter I’d change my mind. All I’m saying is that there are other alternatives!)