Originally posted by Jonathan Mac I would take the 20-40mm over the 21 and 40. I'd be frustrated at the f/4 limitation at 40mm but the 20-40 is better at the wide angle than the 21 is.
I've seen this being said here before, and I'm not disputing it, as I don't have the 20-40mm to compare... but my copy of the HD DA 21mm f/3.2 Limited is one of the sharpest lenses I own. It required fine focus adjustment in basically all my bodies but once I did that, what a world of difference... as sharp as my DA 35 Limited on the 24MP K-3 and 20MP K-S2 in medium to long focus distances (I'm not even kidding...) and the colors and color transitions are just superb.
The problem with the DA 21 is that because it's a wide angle lens, when the focus is a big off and needs adjustments, it doesn't really look out of focus, it just looks like it's not quite as sharp as other lenses. When you look at pictures on a smaller screen like a notebook computer, you don't even see that the focus is off, everything seems sharp until you pixel peep, at which point things get uglier.
I'd love to own the 20-40mm one day if it's even better than my DA 21.
Quote: Add in the compact body, WR, in-lens focus motor (even if it's a bit slow) and that it does feel like a Limited despite being a zoom, I think it's the better choice. Ideally I'd have the 40mm too because it's much smaller and the difference between 2.8 and 4 is appreciable for things such as portraits.
Even better would be pairing the 20-40mm lens (if that ends up being the lens for the OP) with a 50mm or 70mm lens for portraits (or even the FA 77mm Limited if one can afford it...), which would give even better subject isolation and smaller apertures.