tat3406 wrote in post #16441261
What the pro and con compared to your 17-40?
I also have 17-40, thinking to buy this 20mm when travel light.
Pros over the zoom: smaller, lighter, very nice focusing scale, manual focus ring is very nice to use, you can rack it out to infinity with no problem. I haven't done exhaustive IQ tests but I'd say compared to the zoom @ 20mm they are very comparable at smaller apertures maybe a slight edge to the prime (of course I'm biased so take that for what it's worth). I can't really say how they compare wide open as I don't get worked up about edges and corners if I am shooting wide open with any lens.
The zoom, of course, zooms, has auto focus and is reasonably small and light for a high quality zoom. Add the hood and it gets pretty obnoxious, though. The focus scale on the zoom is useless for any type of hyperfocal or zone focusing. Manually zooming to infinity is not really possible w/ Canons buffer zone. Though, AF works fine in that regard.
All that said I only use the zoom when I know I will need AF to get the shots AND if I know I'll need multiple focal lengths quickly. In other words for my style of photography the prime(s) gets the nod 95% of the time.