I will first assume you know what you are doing. :bsmilie:
The lens and camera must be perfectly calibrated for each other. You can read more
here.
That said, the 50 f/1.8 is rather notorious for AF issues due to its old micro-motors design.
Since you only own one camera body, I suggest you bring all your lenses + camera to CSC for calibration. If the camera body is under warranty, it's free.
The following methods are commonly used to determine front/back focus issues:
a) Angled AF chart (free).
See here.
b) Moire patterns on computer monitor (free).
See here.
c) Distant block of apartments:
d) Books or 9V batteries
e) LensAlign Pro (costs S$300 incl shipping).
Read this.
Method (a) and (b) can be dismissed immediately. (a) requires strict 45 deg angle alignment which is rejected by Chuck Westfall (
Read more here). (b) is hardly sensitive.
Method (e) is expensive but does NOT yield more reliable results than (d). Firstly, the targets used in both methods are relatively small and are therefore suitable only for checking near focus accuracy. Secondly, achieving perfect parallelism between the focal and target planes is not essential; near parallelism is good enough. I know 'cos I own (e).
Method (f) is suitable for checking far focus accuracy.
The best technique combines method (c) and (d).
Please first make sure YOU are not the one causing the problems. :bsmilie:
[/QUOTE
Hi bro...
Hmmm...What's method ( f ) ???