I have been facing autofocus issue with Tamron 70-300mm VC USM lens on Nikon D5300. The camera autofocuses fine through viewfinder but it is not able to autofocus at all in liveview, the lens just hunts for autofocus but not being able to autofocus in the end. The camera autofocuses fine in both liveview and viewfinder with all other lenses, which rules out the possibility of being something wrong with the camera. The Tamron lens was working fine like a week back and it suddenly started having this issue. I need help on what might be the cause of this and how to get it fixed. Thanks.

P.S: There are some dirt particles when i look through the viewfinder but it doesn't affect the shots. Just for FYI.

  • 2
    What are the lighting conditions in which you're having problems? Did you recently drop or hit the lens/camera against anything, even if contained within a padded case? Did you update firmware or change any settings, such as focus mode? What were the other lenses that you tried? Third-party lenses tend to have problems that first-party lenses do not.
    – xiota
    Oct 31, 2018 at 7:10
  • Hi Xiota...thanks for the response...I have tried in both indoor and outdoor settings in good lighting trying to focus subjects at different distances but it doesn't work. What really puzzles me is that it is focusing fine through viewfinder. Recently, the only settings I have changed are number of focus points from 11 to 39 and Focus region from Normal to wide. The other lenses I have tried with are Nikon 35mm 1.8, Nikon 18-55mm kit, and Tokina 11-16mm. With all these, it works perfectly fine. Oct 31, 2018 at 12:01
  • @NaquibAlam What happens when you change the number of focus points from 39 back to 11 and the focus region from 'wide' back to 'normal'?
    – Michael C
    Oct 31, 2018 at 20:12

1 Answer 1


Nikon uses two different focusing technologies. When using the viewfinder, your camera will use the more advanced phase detect system, but when in live view, it uses the more antiquated contrast detect technology. This is why there's such a huge discrepancy in AF performance when using the viewfinder vs LiveView mode.

  • Contrast detect requires the presence of a digital sensor. Phase detect is "more antiquated" because it was in invented before digital sensors were in common use.
    – xiota
    May 25, 2019 at 3:12

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