Originally posted by Stavri (Looking at the plumage) In terms of micro-contrast I feel the D-Fa is ahead Mike, but that's just my personal opinion.
To be honest it's a difficult thing to prove either way, my shots were taken with a k-5IIs and are heavy crops, the 150-450mm pics were taken with a K-3 and had very little cropping from what I could see from the raw files. Saying that my post isn't to attack the Pentax lens (which looks excellent) but more to point out that the Sigma isn't
THAT far away and is a viable alternative especially if cost is an issue.
At the moment I am holding off buying the 150-450mm as I do a lot of airshow photography so I want to see shots taken with it on a K-3II that show AF speed/tracking accuracy before I drop the best part of £3k on a camera and lens .... my second option being to upgrade my Canon gear to the 7DII and 100-400mm MKII (but I'm really hoping it doesn't come to that)