Need help with D90 autofocus problem

[SaraJane]

For a few weeks now my D90 is not focussing properly! I have tested it out and it is consistently focusing a little too far behind every time. I am using the Nikkor 35mm f1.8 lens. It's most noticible with a big apperture obviously which is a PITA because I'm usually shooting at 1.8 or 2.

Anyone had this problem and know how I fix it??

[doxastic]

Are you using manual or auto? What about the metering mode?

[SaraJane]

Yep, manual.
Spot metering.

[OsmosisStudios]

Youve probably only noticed it recently or, if the 35/1.8 is new, you hadnt seen it, but this is a fairly common issue among ALL cameras: Your camera body is backfocusing. Its usually not enough to make a difference, but it can be really bad with the wrong lens/body combo. The D90 doesnt have AF microadjust, so thats kind of out of the question.

Your option is to send your kit (body, lenses) to Nikon and have them calibrate the lot together.

[doxastic]

Ok. Play with the opt near the view finder. Get a lense with auto focus, auto focus on to something really close to you and keep turning it until it seem in focus to you. Had the same problem turned out to be someone played with it. Also watch out for the shake and maybe look and see if the lense is clean, with macro you got be spotless.

[sk66]

As mentioned, make sure the viewfinder is properly focused (diopter adjustment near eyepiece). The text etc should be crisp in the viewfinder.
If that's not the issue then it's back focusing as Os mentioned. Back focus while manually focusing would generally only occur if the diopter isn't set right or you are using the focus confirmation light to indicate focus. But the mirrors can be misaligned slightly.
Back focus with autofocus is much more common.

Back/Front focus issues can be adjusted (Nikon wouldn't be too happy about a user doing it though). However, the "issue" can be different with different lenses, so if you tune your camera for the 35mm then it may cause issues with other lenses.

[SaraJane]

Thank you!! Adjusting the viewfinder has helped. I'm still trying to work out if it's perfect or not, it might be just a smidge off still but it has improved A LOT.
Thanks so much!!