D5300 auto focus issues !

[Frenchymn]

Hi all,

I have researched this extensively and I have yet to find a solution.

My D5300 never ever auto focuses when using the view finder, no matter what mode afs, afc, full auto, anything ... That's in all modes too. I use the kit lens and another 18-35 f1.8 Sigma and both behave the same as far as that goes (yes the lenses are physically set to AF and not MF).

In live view it will focus ONLY in AF-F which is what I have been using but that's far from optimal. In AFS the red square stays red and never focuses (half way depressed), therefore the pictures are always blurry.

Does anybody have an idea of what's going on? I have done a factory reset 3 times already too ...

Thanks guys !!
Ben

 

[KmH]

When using the viewfinder (main mirror is down) the camera is sending by reflection what the lens 'sees' to the AF module which uses phase-detection AF.
Note that the phase-detect AF module is in the bottom of the camera, under the mirror box. The main mirror has a portion that is only 50% reflective so what the lens 'sees' goes through the main mirror so it can be reflected down to the AF module by a smaller second mirror behind the main mirror.
That second, smaller mirror is not doing it's job for some reason.

It's likely your camera needs to be repaired. You need to have the camera looked at by Nikon, or a Nikon authorized repair shop if the warranty has expired.

When using live mode the main mirror is up and the camera is doing contrast-detect AF via the image sensor, not the AF module and that smaller secondary mirror and the main mirror are up out of the light path and aren't being used.

 

[Frenchymn]

Thank you so much @KmH for the thorough explanation !
Is there any way I could clean this mirror or any simple maintenance before sending it out to get checked ?
Thanks !

 

[astroNikon]

Thank you so much @KmH for the thorough explanation !
Is there any way I could clean this mirror or any simple maintenance before sending it out to get checked ?
Thanks !

If you are a Nikon service center then there's plenty you can do.
Otherwise, no.