I have great news.. my 2nd copy is a keeper
Albeit with a -2 microfocus adj. on my K7
But here's the ghost I am unable to decipher. When I first did a formal test with charts/tripod in bright daylight (diffused and indirect), it clearly and consistently (well, almost) showed a need for a -8 microfocus adj. at all subject distances I used (1/2/3 m). I took multiple shots per test scenario just to cover up false results (yes, it is inconsistent sometimes. It's a machine). BUT, BUT BUT...
BUT.. the moment I shot some test shots in the real-world freehanded, it consistently showed BF (will post the pics). By trial and error (hand held) I found a -2 microfocus adj. to be correct. With this, shot after shot (with some acceptable inconsistency) showed spot on focus at -2 microfocus adj. Then what the hell was that formal test result of -8???
I felt it was in flurascent lighting, while the testing was done in daylight. But, to my surprise, when I took the lens out the next day(light), the -2 microfocus adj. seemed fine for everything (except a near infinity AF it did on a flying airplane.
There is definitely something to this. Maybe the test chart itself. But for now, I'm happy that it is quite consistent with this copy 2. Almost spot on focus except in the most difficult conditions. As opposed to my copy 1 that was behaving very inconsistently. Perhaps like what Rob noticed with his Sigma 50 1.4. And my copy 2 was more contrasty (signature Sigma contrast) than my copy 1. Also my copy 2 shows almost no difference when stopped down or for different subject distances, while the copy 1 was slightly crazy with subject distance. So I declare the copy 1 as faulty.
Some things I observed about the Sigma 85mm F1.4, compared to the Sigma 50mm F1.4
1. The 85mm is slightly less sharp than the Sigma 50mm F1.4, @ 1.4. Maybe given the extra FL
2. 85 is as contrasty as 50mm
4. The 85's AF (maybe in combination with my K7 copy) is almost immune to stopping down and to different subject distances. The 50mm's AF varied a lot with stopping down and different subject distances. Very un-handlable (for lack of a better term). However, this is a known behavior among superfast lenses. But it's surprising that the 85 is this immune.
5. The 85mm seems to require a lot of contrast in the subject to be able to AF lock. In some other strange situations, where there is plenty of light (even daylight) and plenty contrast in the subject, the sigma finds it very tough to AF.
Thanks to all you folks for sharing your knowledge. Images will follow in my subsequent post.
Cheers,
Anil