I don’t do technical too much here. There’s a wealth of knowledge out there on t'interweb for almost all queries and aches and pains when it comes to photography. If you’re an X-Pro1 user one of the nicest parts of ownership is the optical viewfinder it comes with and one of the main reasons why the X-Pro1 has sold so well. Many photographers still like a traditional optical viewfinder, and with EVF’s still playing catch up, the Fuji XP1’s OVF remains one of the nicest out there.
However, one area that appears to be a grey area for some is the corrected AF option for the X-Pro1 and how to fully understand it. Simply put, traditionally DSLRs focus your camera on an image, and is seen through the viewfinder by way of the image hitting the lens and being bounced upward and through the viewfinder.
The problem is the X-Pro1 is a mirrorless camera and so the OVF has to work in a rather clever way to work as it does.
Effectively when you look through the optical viewfinder you are looking through a different lens. The OVF is in a different position to the camera lens, and in order to compensate for this, the X-Pro1 uses parallax correction.
Parallax error is more enhanced when the image you are looking at through the OVF is close at hand. Scenes further away show less parallax error, and so what you see requires less correction.
In the case of the X-Pro1, when you look through the OVF the focus box and half press the shutter, the frame will move down and to the right. This is effectively what the lens of the camera sees and focusses on and the OVF is correcting the error for you. The autofocus point moving is the camera telling you what you are actually focussed on and is designed to show what your image will look like, allowing for parallax adjustment.
To use the corrected AF menu item you need to have the corrected AF setting switched on in your menu. Compose your image as you see it through the OVF, and when the shutter is half pressed, amend your image composition accordingly. Now, this will record the image as you want with the corrected AF working to your advantage.
It makes the camera and the image taking a little more deliberate, but in some instances more enjoyable, and of course if you’re struggling with it, you can always flip over to the EVF (electronic viewfinder) which has none of these issues to contend with.