The problem is that the camera plus the 35mm Lens are not focusing properly, by that I mean that is focusing just tad in front of my subject.
Conditions of my tests
- D7100 + 35 1.8mm both bought new.
- Target at 3 feet (1 meter) away from the lens, high contrast lines at a 45°
- On a tripod, tripod did not move.
- Lens at 1.8 for shallow DOF
- Autofocus set to AF-S, center point, on a timer to avoid motion blur (Speed was somewhere 1/320 but just to be sure).
Tests:
1. Focus fine tune set to OFF.
1.1 After 5 shots I noticed that the camera was focusing somewhere around 1 cm too close (0.3" inches).
2. Focus fine tune set to ON
2.2 +5... no changes
2.3 +10 no changes
2.4 +20 it gets a little bit better.
2.5 - 5 it changes a lot for the worst, it focuses even more closely than before.
2.6 -20 WORST, it's focusing way way closer.
2.7 Just for the kicks I change the default value to - 17 and it gets better. Still not spot on, but better. So it gets: Default value -17 and Saved value +20 and focus is ALMOST perfect.
So I wonder, why can't I move the focus point forward (Away from the camera)?
I also noticed after a few more shots lowering the F value that the focus point actually moves away. At F/8 focus looks perfect given the increased DOF, but it is actually about half an inch off away from the lens.
Another thing, I don't know if related but, when Selecting AF-A - AUTO, the camera has a tendency to "prefer" the left sensors on normal basis.. But for example if I shoot a blank wall with detail on the RIGHT it has no problem selecting the RIGHT sensors.
I'll appreciate any help I can get. I'm going PRO, can't afford new equipment at the moment and it's a real pain to take portraits out of focus.