Gray Hawk in flight. Photo by Eduardo Libby

Nikon’s Z7 requires AF-Fine Tuning

The claims that on-sensor phase-detection autofocus sensors in Nikon’s Z7 does away with autofocus fine-tuning are wrong. I had to use AF Fine Tuning to get my lenses to focus properly.

When I first started using my Nikon Z7 for wildlife photography I got some very nice and sharp images, along with other photos where the focus was not perfect. I assumed vibration or wrong sensor group choice were the cause. However, when I tried longer distance shots I found my images were consistently not sharp.

Broad-winged Hawk with prey. Photo by Eduardo Libby
This photo of a Broad-winged Hawk eating a snake was sharp enough, but the Hawk was only about 10 m away. The featured image of a Gray Hawk in flight was not sharp, although it looks fine at this size on screen. All images were made with Nikon AF-S 300 f/2.8 VR and TC-20EIII extender.

Even though I initially believed web articles stating that with the phase detection AF sensors on the sensor plane AF-fine tuning is unnecessary, further research told me that there are other aspects of phase-sensitive focusing that still require calibration. An excellent post by Roger Cicala about how autofocus works shows for example how different sectors of the image are optically split and how the separation is used for autofocus. Here is the link for this post:

https://www.lensrentals.com/blog/2010/07/how-autofocus-often-works/

Torrent Tyrannulet. Photo by Eduardo Libby
The Torrent Tyrannulet was about 20 m away, and I could not get a sharp shot until I focused manually. This was the moment when I realized AF-Fine Tuning was necessary.

After reading Roger’s post I understood why cameras like the Olympus OM-D EM-I mark II have an AF Fine-Tune setting, and why it was also included in the menus of the Nikon’s Z7 camera.

The Nikon Z7, just like other Nikon DSLR cameras in Live View, uses Contrast Detection Autofocus when in AF S mode but seems to use it only as a fine adjustment to the main Contrast Detection AF. This is why AF Fine Tuning is important in both AF C and AF S modes.

Have you had to fine tune the focus for your lenses too?

4 thoughts on “Nikon’s Z7 requires AF-Fine Tuning”

  1. I have to fine-tune my D500. I watched the video by Steve Perry of Backcountry Gallery and he has tips on how far away to place the target, the lighting, etc. And While I know it is not such a daunting job, I have to gird my loins to do it. 🙂

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    1. Hello David, my D500 required more aggressive fine tuning than the Z7. I really find useful the commercial focusing targets, although you can make do with homemade devices. Just take your time! At least I haven’t had to do it again…
      Eduardo

      Liked by 1 person

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