sigma 18-200 focus problem

[punchyjam]

Hi , I am looking for some help , i am relatively new to photography, i have a nikon d5000 with sigma 18-200 os lens. Please forgive my lack of proper terminology but i have been finding that when i am shooting at the 18mm end of the lens the focus is terrible , i have tried many different shutter speeds and aperture setting to correct this with no luck, zoomed in the focus is good. can anyone help me , camera is around 12mths old and the lens is 6 mths old. Many thanks in advance

[donoreo]

You probably want to test the focus to make sure, unless it is so bad it is plainly obvious. There could be something wrong with the lens. I would take it into where you bought it and let them have a look. The lens would still be under warranty.

To test the lens, I think there might be a tutorial on the site here somewhere.

[punchyjam]

thank you for the reply , one thing i did not mention is that if i manually focus the result seems much improved, as i said i am a newbie here , would the shop i bought the lens from be able to test in in store?

[donoreo]

Originally Posted by punchyjam

thank you for the reply , one thing i did not mention is that if i manually focus the result seems much improved, as i said i am a newbie here , would the shop i bought the lens from be able to test in in store?

Most likely. If there is a noticeable difference between autofocus and manual focus they should be able to see that.

[OldBoy]

Try switching off OS and see if that makes a difference. It could be a that the OS on wide angle is causing the problem