Something happened over 10 years ago when my everyday camera was a Canon 20D coupled with a Canon 28-135mm f/3.5-5.6 IS USM lens.
This was a zoom lens I inherited from the film days. It was certainly better than the cheap plastic kit-zooms that used to be sold in a bundle with SLRs and DSLRs, but certainly not a high quality prime lens. It was something in-between, and it was good enough for me. In a nutshell, an efficient lens and a reasonable all-rounder.
Now coupled to a digital body though, for the first time its results were being scrutinised at the pixel level – and I started to think the lens was crap because it was everything but sharp. I felt the need to upgrade to something better and more expensive, probably from the prestigious Canon L family sporting that famous red ring.
Then one day I was shooting for a project in a low-light setting. I had to use a tripod – a very cheap one. The setup made me stop down the lens to small apertures and get long exposures.
Later at home, when I downloaded the images to my computer, my jaw dropped. Coming out of that lens, the photos were sharp. I was astonished.
Your sharpest lens is a tripod.
This was a lesson to me. Talking of sharpness alone, I realised what really differentiates an expensive prime lens from a cheaper lens it’s the ability of the prime to deliver in all conditions, especially wide open. Current primes will effortlessly give you razor-sharp outputs at f/1.4, corner to corner, if needed.
A cheaper lens will fail to deliver the same sharpness wide open, whatever its largest aperture. However, stop it down all the way to f/8 and it will get there. It will match, or at least get very close, to a prime’s sharpness level.
So if you are on a tight budget and unable to afford a sharp prime lens, don’t you worry. Get a tripod – a cheap one – and it will become your sharpest lens.