Sounds like Store Points By Orientation. I cover in the Z8/9 guide, but here's an excerpt:
Store Points By Orientation
This function will remember where you had the AF point the last time your camera was in a vertical orientation and then where it was the last time the camera was horizontal. At first, this may seem about as handy as a trap door on a canoe but stick with me here.
Think of this scenario. Let’s say you were photographing the feathers off a beautiful egret that was standing in the marsh, and you have your camera vertical with one of the outside AF sensors plastered to his eye.
However, in the meantime, there are a few birds occasionally flying by and you want to use the middle AF point with the camera in a horizontal format to capture those.
Normally, you’d have to move those AF points around each time you switched orientations and probably miss shots. With this turned on, you can turn the camera horizontal when the flyers sweep by and your AF point will jump back to the middle. Once they pass, you can turn the camera back to vertical and the AF point will jump right back to where it was before.
Another handy use for
Store Points By Orientation is when your’re waffling between a vertical and horizontal version of an image. As the bee eater (above) shifted around, I swapped between horizontal and vertical shots and it was handy to have the AF area move to the proper place (well, pretty close) each time I changed orientation.
Oh, but it gets even better!
With a Z8/9, you can also choose between just remembering the AF point position or remembering the AF point position
and AF area! So, that means you can shoot the standing bird with Single Point AF and the flyers with Wide AF –
and the camera will switch back and forth whenever you change orientations!
For example, take a peek at the panel below. In vertical orientation, the camera is set for a single AF point towards the top of the frame, but while in a horizontal orientation, it’s set for Wide (S) and more towards the center.
When I’m shooting the heron (left), the camera is using Single Point AF and the AF position is towards the top. However, when I spot the egret flying past and turn the camera horizontally, the camera moves the AF position towards center
and changes it from Single Point AF to Wide (S) AF.
All automatically!
To enable, head to the
Store points by orientation menu. Click
Focus point or
Focus point and AF-area mode from the resulting menu.
Field Usage
Setup for all of this is simple once it’s turned on.
For just the
Focus point option, flip your camera to the orientation you want (vertical or horizontal), and move your AF point into position – that’s it! Each time you rotate the camera, it will go to wherever the AF point was the last time you were in that orientation.
If you’re using this with the
Focus point and AF-area mode option, flip to the orientation you want, position your AF point, and then switch to the AF Area Mode you want – all set. This works just like the Focus point option, but it takes the AF Area Mode along for the ride.
Although this feature may have you more excited than a teenage girl at a Taylor Swift concert, there is a note of caution.
Often people will enable this feature, not use the camera for a while, and then find themselves flabbergasted when the camera is switching AF positions and AF areas when they swap orientations. So, if you ever find yourself resembling that remark, hopefully you’ll recall this little note and save yourself some confusion.