Originally posted by dmytty The 400mm APO Macro with 77mm thread seems to be very well reviewed - by those who have it. However, it also appears that this lens is a rare bird. Are there more owners out there?
In 2012, it's amazing that Pentax can barely beat this 10+ year old lens...and Pentax is at 10x the cost!
I just got one this week off eBay. I'd been watching for about a year, ever since I got my K-30 and started looking into telephoto lenses. I got a Sigma 400mm f5.6 AF (non-APO) last year. I did my first tries at comparing them today (but on swans, not on something fixed that would give an exact A/B comparison). I was surprised that some of the photos with my old Sigma were just as sharp and some with this lens - but they had purple fringing, whereas this had absolutely none. I hadn't thought that I would care about the macro focusing, since I have other lenses for that, but it is actually very handy. I posted one swan picture I took today in the Nature section of the photo gallery.
So, so far very pleased (well, I wish it had been cheaper...), but I need to do more testing to see if it is really sharper/more contrasty than my old lens, as well as being apochromatic. The pictures I've seen posted indicate it can be amazingly sharp in the right circumstances/hands.