Chosen Solution
i never had this problem before. i had the 18-55mm kit lens, it focused fine. and then recently bought a new sigma 18-250mm lens, and suddenly i’m getting soft photos. i lately realized it wasn’t a lens quality problem, it was back focus. when i’m shooting portraits for example, i keep a focus point on the eye, but what i’m getting in focus is an ear or something!! this is persistent in every focus mode, and at all focal lengths. i think its getting worse with time, it started with like 30% of the shots, now its like 90% is OUT OF FOCUS SHOTS! what do i do guys, help me.
I most likely is focus shift - and a ‘bad lens’. If you can, you should return it for a properly working one. try shooting ‘full open’ and see how the results are - if they are better, its focus shift. if its not focus shift, then maybe the lens can be fixed by a qualified technician - not sure how ’easy’ the are to work on.