Overview.
To perform focus control of the lenses attached to your camera, whether electronically in
the case of the Blackmagic Pocket Cinema Cameras or physically through an attached
Tilta focus motor, each lens must have its focus positions mapped to a specific distance.
This is achieved with a semi-automated calibration process with the AFX moving the lens
to a set of focus positions, you moving the camera until the subject is in focus and, once
confirmed, the range sensor capturing the value of the distance to the subject.
This calibration procedure is performed once for each lens and the resulting data
generated is then stored in a
CALIBRATION FILE
in the AFX’s
LENS DATABASE
.
The
CALIBRATION FILE
is then loaded from the
LENS DATABASE
each time the
specific lens is subsequently used and up to 128
CALIBRATION FILES
can be stored on
the AFX.
To aid with the calibration process, you can download the focus target chart above from
our website at www.cdatek.com and either print it out or display it as an image on a tablet
or monitor screen.
The accuracy of the AFX’s auto-focus performance for each lens is directly linked to the
accuracy of its initial calibration so it cannot be stressed enough that care must be taken
to follow the calibration procedure correctly and allocate a suitable amount of time to do it.
The amount of time will vary between approximately 5 minutes and 20 minutes depending
on the lens type used as the AFX uses a different number of calibration “
TRACKS
” for
different lens types but this will only ever need to be done once for each lens.
IMPORTANT NOTE :
If you are using an
MMX
it must be active for all
CALIBRATION
steps.
AFX USER GUIDE
WWW.CDATEK.COM
8
FIRST LAUNCH - Lens Calibration Intro
