Originally posted by stevebrot I tried backing off with my lenses, but even the slightest movement off mechanical hard stop put the plane of focus much closer than 100 yards.
using magnification in the lcd, does it look like the lens rotates past the focus point at 100 yards? because with cheap adapters on mirrorless, the register distance is slightly less, in order to guarantee focus ring rotation beyond what passes for infinity focus, when the lens is on a dslr... so you can smoothly approach the 100 yard mark from either direction, which minimizes the backlash effect.
with many lenses, the rotational distance to sharp focus, when you are within several feet of the target area at 100 yards, is less coming into it from the backside of the focus point... so you rotate back and forth to establish both ends of the focus range, then stop right after creeping into it on the back rotation stroke.
but that still may not be enough; modern lenses, as gofour3 alluded, have better coatings, and they can sometimes blip a very small focus peaking mark, even wide open, using a wide angle lens at a distance that's so long i can't discern maximum sharpness in the evf, even with 14.4x mag... the fa35/2 can do it in that scene, but even better, is the korean 35/1.4 lenses, here at f/2, at 300+ yards?
https://www.dropbox.com/s/0gxrx5uebxgstlk/DSC03353at2point0.JPG
when you have perfect focus like that, it's easy to see all of the problems with those junk korean lenses... fwiw, the mf functionality on that lens is very good, which addresses the point you were making.
Originally posted by stevebrot That being said and totally shifting topics, I agree with monochrome that there may be something wrong with your lens. Other than the center third, the image in the K 28/3.5 version is not just soft, it is smeared.
on page 2 of this thread i clearly stated "i'm writing that situation off to copy variation with the k28/3.5"
so we have all been in agreement there, all along.
point is, copy variation trumps everything, if we are going to talk about older and forgotten lenses being revived on the new pentax ff camera, we'd better know how to test for the problems.