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AF Button/Back Focus

Posted 01/11/2023 - 18:11 Link
On my K3ii I'm trying out back focus using the AF button. I seem to of got it working, but not sure if it's right.
Am I right to say that when focusing with the AF button, keeping it pressed in I'm able to move to another subject and it will re-focus. In my case that isn't working. I have to keep repressing the AF buton to re-focus.
It works in AFC
Works in AFS, but only when repressed.
Don't understand AFA
Posted 01/11/2023 - 19:49 - Helpful Comment Link
Sounds like it's working as it should. The back button is replacing a half press of the shutter button, the action of which is given in my K3 manual as "When the shutter release button is pressed halfway and the subject comes into focus, the focus is locked at that position.".

From the camera's point of view, when you move to another subject it's just an example of the subject moving on the sensor. The camera doesn't know (or care) whether that's due to the subject itself moving or to you moving the camera. Adjusting focus when the subject is moving on the sensor is what continuous AF is for.

It's worth persevering with back button focus. Many of us find that focusing and refocusing is easier when focus and shutter release are done separately rather than by the same finger. It's just a matter of training the thumb to do something different to what it's been doing for most of its life .

Posted 01/11/2023 - 22:40 Link
I would try to use the joystick to move the focus point. I had the same issue and now find this second nature.
'Life looks simple through a viewfinder'.....then I went Digital!
K3 III, DA* 16-50, HD DA 16-85, DA* 50-135, DA* 300, HD 55-300 PLM, HD 1.4x, AF360
Posted 01/11/2023 - 23:30 Link
Snappyhoffy wrote:
I would try to use the joystick to move the focus point.

No joystick on the K3ii, it appeared with the K3iii. Presumably changing the focus point with a K3ii is the same as with the original K3 i.e. press buttons to move among the focus points. It can be done, but the joystick on the K3iii is much easier. Even then with AFS you still have to press the back button again to refocus.


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