Yes you are correct with the number of blades. Still can't quite decide and on the plane in 12 hours! Do I have room for both?

Another Pentax Forums member here. I'm growing to like my FA20-35 more and more (I acquired one secondhand about a year ago). To the point where it's pushing my Tamron 17-50 off my camera for many uses. There is something about the rendering that's very attractive. And the lightness/compactness is a real plus. The only real let down vs the Tamron is night time star bursts. The Tamron does a really good job of these at F11 whereas the FA20-35 is quite ordinary. Difference in the number of aperture blades probably accounts for this. I think the FA 20-35 is about to come with me for a business jaunt to Europe/HK instead of the 17-50 so we'll see what it can produce ...it's only the star burst question that is making me question which of the two to take.

Don't forget that we all like larger, higher res rear screens. That real estate in turn needs larger batteries. Both mean more weight.

Also to compare the pro grade magnesium body and water proofing of a K-5 with lower- end dLSRs is not an apples to apples comparison. WR and mag bodies are not a free lunch weight-wise. Nor is more shots/charge. I've picked up the lower end Canon bodies - feel very flimsy vs even my K-x.

Let's not get too hung up with a few grams here and here.